Jet lag-like sleep disruptions spur Alzheimer's memory, learning loss

October 29, 2015
Science Daily/University of California, Irvine
Chemical changes in brain cells caused by disturbances in the body's day-night cycle may be a key underlying cause of the learning and memory loss associated with Alzheimer's disease, according to a new study.

The research on mice, led by UCI biomedical engineering professor Gregory Brewer, provides the first evidence that circadian rhythm-altering sleep disruptions similar to jet lag promote memory problems and chemical alterations in the brain.

Clinical application of this finding may lead to more emphasis on managing the sleep habits of people at risk for Alzheimer's disease and those with mild cognitive impairment. Study results appear online in the Journal of Alzheimer's Disease.

People with Alzheimer's often have problems with sleeping or may experience changes in their slumber schedule. Scientists do not completely understand why these disturbances occur.

"The issue is whether poor sleep accelerates the development of Alzheimer's disease or vice versa," said Brewer, who's affiliated with UCI's Institute for Memory Impairments and Neurological Disorders. "It's a chicken-or-egg dilemma, but our research points to disruption of sleep as the accelerator of memory loss."

In order to examine the link between learning and memory and circadian disturbances, his team altered normal light-dark patterns with an eight-hour shortening of the dark period every three days for young mouse models of Alzheimer's disease and normal mice.

The resulting jet lag greatly reduced activity in both sets of mice, and the researchers found that in water maze tests, the AD mouse models had significant learning impairments absent in the AD mouse models not exposed to light-dark variations and in normal mice with jet lag.

In follow-up tissue studies, they saw that jet lag caused a decrease in glutathione levels in the brain cells of all the mice. But these levels were much lower in the AD mouse models and corresponded to poor performance in the water maze tests. Glutathione is a major antioxidant that helps prevent damage to essential cellular components.

Glutathione deficiencies produce redox changes in brain cells. Redox reactions involve the transfer of electrons, which leads to alterations in the oxidation state of atoms and may affect brain metabolism and inflammation.

Brewer pointed to the accelerated oxidative stress as a vital component in Alzheimer's-related learning and memory loss and noted that potential drug treatments could target these changes in redox reactions.

"This study suggests that clinicians and caregivers should add good sleep habits to regular exercise and a healthy diet to maximize good memory," he said.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2015/10/151029103405.htm

Scientists work with artists to learn more about the brain

November 13, 2015
Science Daily/University of Houston
Researchers have analyzed brain activity data collected from more than 400 people who viewed an exhibit at the Menil Collection, offering evidence that useable brain data can be collected outside of a controlled laboratory setting. They also reported the first real-world demonstration of what happens in the brain as people observe artwork.

https://images.sciencedaily.com/2015/11/151113050945_1_540x360.jpg
Woman looking at paintings in art gallery (stock image). New research has found significant increases in functional, or task-related, connectivity in localized brain networks when the subjects viewed art they considered aesthetically pleasing, compared with baseline readings. Differences were found both between men and women, and between the youngest and oldest subjects.
Credit: © Kaspars Grinvalds / Fotolia

"You can do testing in the lab, but it's very artificial," said Jose Luis Contreras-Vidal, Hugh Roy and Lillie Cranz Cullen Distinguished Professor of electrical and computer engineering at UH. "We were looking at how to measure brain activity in action and in context."

The researchers reported their findings in the journal Frontiers in Human Neuroscience. In addition to Contreras-Vidal, the research team included Kimberly Kontson and Eugene Civillico, scientists with the U.S. Food and Drug Administration; artist Dario Robleto; Menil curator Michelle White, and Murad Megjhani, Justin Brantley, Jesus Cruz-Garza and Sho Nakagome, all of whom work in the UH Laboratory for Non-Invasive Brain Machine Interfaces.

The research found significant increases in functional, or task-related, connectivity in localized brain networks when the subjects viewed art they considered aesthetically pleasing, compared with baseline readings. They found differences both between men and women and between the youngest and oldest subjects.

"The direction of signal flow showed early recruitment of broad posterior [visual] areas followed by focal anterior activation," they wrote. "Significant differences in the strength of connections were also observed across age and gender. This work provides evidence that EEG [electroencephalogram], deployed on freely behaving subjects, can detect selective signal flow in neural networks, identify significant differences between subject groups, and report with greater-than-chance accuracy the complexity of a subject's visual percept of aesthetically pleasing art."

Kontson, a biomedical research fellow at the FDA who led the research during a post-doctoral fellowship, said researchers started with three questions: Can useable brain data be collected in an uncontrolled setting? How well do different models of EEG headsets perform? Is it possible to collect substantial amounts of data relatively quickly?

EEG headsets are considered medical devices if intended for use in the diagnosis of disease or other conditions. Kontson said the FDA is interested in the potential use of large and complex data sets -- "big data" -- for regulatory decision-making.

Data was collected from 431 people as they viewed Robleto's solo show at the Menil Collection in Houston, "The Boundary of Life Is Quietly Crossed," a sculptural installation that included both visual and aural representations of the heart. Researchers categorized each piece as either complex or moderate; they also asked each participant to face a blank wall for one minute before entering the exhibit in order to obtain baseline data.

The Frontiers in Human Neuroscience paper is based on data from 20 people who wore a reference gel-based EEG headset; Contreras-Vidal said findings from those who wore one of four models of dry-electrode headsets -- easier to use in public, as they require little preparation or instruction -- will be reported later, as will an analysis on data collected with the dry headsets.

The initial results allowed researchers to predict from the brain activity with 55 percent accuracy whether the participant was looking at a complex piece of art, one categorized as moderately complex or a blank wall. That compares to 33 percent accuracy for random prediction.

The knowledge could have varying applications. Much of Contreras-Vidal's recent work centers on using brain activity to help people with disabilities use bionic hands or to regain movement by "walking" in exoskeletons powered by their own thoughts. He sees this research with artists and museum-goers -- a related project collects brain activity from dancers, visual artists, musicians and writers -- as potentially leading to technologies that can restore sensory processing in people with neurological impairments.

Artists and museum curators could use the findings to learn more about how museum displays affect the way people move through and react to an exhibit, which works are preferred by museum-goers and other information, Contreras-Vidal.

But he doesn't expect the research to produce a how-to on creating art.

"I don't think we will understand the mystery (of how art is created)," he said. "The conception of art is a very individual process, built on the artist's experiences, skills, memories, values and drives. But we will know what happens in the brain. We might find that there are people who are very attuned to visual art, or to music, or poetry, and there might be an underlying common neural network. If we know that, we could optimize the delivery of art for therapy, for teaching."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2015/11/151113050945.htm

Understanding why group singing helps in dementia

December 3, 2015
Science Daily/British Psychological Society (BPS)
Couples where one partner is suffering from dementia can benefit from taking part in group singing.

That is the conclusion of research being presented today, Friday 4 December 2015, at the annual conference of the British Psychological Society's Division of Clinical Psychology in London.

Shreena Unadkat from Salomons Centre, Canterbury Christ Church University, interviewed 17 heterosexual couples where one partner had dementia.

The couples described various benefits they received from taking part: the pleasure of singing, the friendship and wider social life fostered by membership of a group and being able to take part in activity together as equals. Some couples said the experience had increased their sense of togetherness and "breathed oxygen into the relationship." Interestingly, the strongest benefits were reported when couples took part in learning or performing new material, not just singing reminiscence songs.

The partners with dementia said that taking part in group singing increased their confidence and gave them an identity beyond their diagnosis. The partners who were the carers reported a release from burden, a sense of liberation and enjoyment.

Shreena Unadkat said: "Singing groups can provide couples with an opportunity to take part in an activity on an equal basis; something which can be difficult when one partner is the lead carer in outside life. Additionally, couples who learnt or performed new materials reported the greatest benefits, which is interesting considering many dementia therapies are based on reminiscence. This understanding may have implications for psychological therapists' involvement in dementia care."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2015/12/151203203625.htm

People with dementia exposed to low quality of life through lack of activity

December 4, 2015
Science Daily/Griffith University
People with dementia living in long-term care often show low levels of activity participation, which negatively impacts their quality of life, say researchers.

Quality of life for people with dementia living in long-term care is often negatively impacted due to low levels of activity participation.

Furthermore, staff and families remain pessimistic about the abilities of the person with dementia to be engaged.

These are among the findings of a large-scale national study on the quality of life of people with dementia in residential aged care undertaken by the Dementia Collaborative Research Centre and Griffith University.

The study will be presented at this week's 11th Gold Coast Health and Medical Research Conference (Dec 4 and 5) by Professor Wendy Moyle from Griffith's Menzies Health Institute Queensland.

Using 53 residential aged care facilities across Australia, the study measured the participation levels across 15 leisure activities for residents with dementia (five items indoors and 10 items outdoors). For the 191 residents who were able to rate their own activity, the average score was 11.4 out of 30, with 0 being the lowest participation rate and 30 being the highest.

Among the 435 staff members surveyed in the study, the average score was 9.6, so lower than the people with dementia who self-reported on activities.

Families were found to be the most pessimistic regarding the degree to which they believed their family member engaged in leisure activities, with an average score of 7.

The study also tested the levels of cognitive impairment (brain function) and found that this was not related to the resident's assessment of their activity participation.

"It is particularly interesting that cognitive impairment was not found to be related to the residents' activity score whereas staff and family members' rating of a resident's activity level was highly negatively related to their cognitive impairment, such that those with more severe impairment were seen as having lower activity levels," says Professor Moyle.

"There appears to be a wrongly held assumption by staff and family that people with severe or late stage dementia are not capable of leisure activity or that they do not require the stimulation of activities.

"However we can see that although these people see themselves as having low ability, they have the capacity for a lot more.

"We already know that activity is really important and just because people with dementia may be cognitively impaired, it doesn't mean that they should miss out on engagement in an activity. Missing out in this way can result in not only further lowering cognitive ability, but also the potential for there being an unmet need in the person. This may be exhibited as behavioural and psychological symptoms of dementia such as agitation and wandering which can also result in an increased need for medication."

All three groups within the study rated those who they saw as more depressed, as having lower activity levels.

"When we looked at the resident's self-report, for example, the more they rated themselves as depressed, the lower they rated their own overall activity level. Among staff the difference was particularly large; they rated those with no depression with an average score of 10.9 versus a score of 6.4 for those they saw as being severely depressed.

"Maintaining quality of life for people with dementia living in long-term care is important, as there is no cure for this prevalent condition," says Professor Moyle. "When people with dementia go into long-term care, there is a belief that they will be more engaged in activities and will experience an improved quality of life. This unfortunately is not always the case.

"Given that leisure activities are proven to be related to the overall quality of life of this group, then there needs to be a concerted look at how this can be improved."

Professor Moyle suggests that higher staff to resident ratios are required in care homes, with the potential for integrating increased numbers of volunteers to provide more leisure activities within the care setting.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2015/12/151204000241.htm

MIND diet repeatedly ranked among best

Included seven times in U.S. News & World Report's 2016 'Best Diets'

January 5, 2016
Science Daily/Rush University Medical Center
A diet proven to lower the risk of Alzheimer's disease by as much as 53 percent in participants who adhered to the diet rigorously has also been ranked as the easiest diet to follow by U.S. News & World Report.

A diet created, studied and reported on by researchers at Rush University Medical Center has been ranked the easiest diet to follow and the second best overall diet (tying in both categories) for 2016 by U.S. News & World Report. The MIND diet also tied for third for best diet for healthy eating and was ranked in the top five in five categories and the top 20 in seven, as follows:

•    Easiest Diets to Follow: No. 1 (tie)
•    Best Diets Overall: No. 2 (tie)
•    Best Diets for Healthy Eating: No. 3 (tie)
•    Best Diets for Diabetes: No. 4 (tie)
•    Best Heart-Healthy Diets: No. 4
•    Best Weight-Loss Diets: No. 16 (tie)
•    Best Fast Weight-Loss Diets: No. 21 (tie)

Now in its sixth year, the annual "Best Diets" list provides the facts about 35 chosen eating plans and ranks them on a range of levels, from their heart healthiness to their likelihood to help with weight loss. To create the annual rankings, U.S. News editors and reporters spend months winnowing potential additions to the diet roster and then mine medical journals, government reports and other resources to create in-depth profiles. Each profile explains how the diet works, whether or not its claims are substantiated, scrutinizes it for possible health risks and examines what it's like to live on the diet, not just read about it.

Eating away at Alzheimer's risk

The MIND diet is a research-based diet developed by Martha Clare Morris, ScD, a Rush nutritional epidemiologist, and her colleagues. In recent studies, the MIND diet showed that it helped lower the risk of Alzheimer's by as much as 53 percent in participants who adhered to the diet rigorously, and by about 35 percent in those who followed it moderately well.

"One of the more exciting things about this is that people who adhered even moderately to the MIND diet had a reduction in their risk for Alzheimers," Morris says. The researchers also have found that adhereing to the diet may slow cognitive decline among aging adults, even when the person is not at risk of developing Alzheimer's disease

The name of the MIND diet is short for Mediterranean-DASH Diet Intervention for Neurodegenerative Delay. The diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. Both diets have been found to reduce the risk of cardiovascular conditions, like hypertension, heart attack and stroke. Some researchers have found that the two older diets provide protection against dementia as well.

Morris and her colleagues developed the MIND diet based on information that has accrued from years' worth of research about what foods and nutrients have good, and bad, effects on the functioning of the brain.

A wine and no cheese party

The MIND diet has 15 dietary components, including 10 "brain-healthy food groups" and five unhealthy groups -- red meat, butter and stick margarine, cheese, pastries and sweets, and fried or fast food.

To adhere to and benefit from the MIND diet, a person would need to eat at least three servings of whole grains, a green leafy vegetable and one other vegetable every day -- along with a glass of wine -- snack most days on nuts, have beans every other day or so, eat poultry and berries at least twice a week and fish at least once a week. In addition, the study found that to have a real shot at avoiding the devastating effects of cognitive decline, he or she must limit intake of the designated unhealthy foods, especially butter (less than 1 tablespoon a day), sweets and pastries, whole fat cheese, and fried or fast food (less than a serving a week for any of the three).

Berries are the only fruit specifically to be included in the MIND diet. "Blueberries are one of the more potent foods in terms of protecting the brain," Morris says, and strawberries also have performed well in past studies of the effect of food on cognitive function.

"The MIND diet is a modification of the Mediterranean and DASH diets that highlights the foods and nutrients shown through the scientific literature to be associated with dementia prevention," Morris says. "There is still a great deal of study we need to do in this area, and I expect that we'll make further modifications as the science on diet and the brain advances. We devised a diet and it worked in this Chicago study," she adds. To establish a cause-and-effect relationship between the MIND diet and reductions in the incidence of Alzheimer's disease, "The results need to be confirmed by other investigators in different populations and also through randomized trials."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/01/160105134102.htm

Zoning out or deep thinking?

Brain scans show that stories that force us to think about our deepest values activate a region of the brain once thought to be its autopilot

January 7, 2016
Science Daily/University of Southern California
Reading stories about values you hold sacred activates a part of your brain once thought to be used for zoning out. The researchers suggest that these results were gained not just because the brain is presented with a moral quandary, but rather that the quandary is presented in a narrative format.

Real-time brain scans show that when people read stories that deal with these core, protected values, the "default mode network" in their brains activates.

This network was once thought of as just the brain's autopilot, since it has been shown to be active when you're not engaged by anything in the outside world -- but studies like this one suggest that it's actually working to find meaning in the narratives.

"The brain is devoting a huge amount of energy to whatever that network is doing. We need to understand why," said Jonas Kaplan of the USC Dornsife Brain and Creativity Institute. Kaplan was the lead author of the study, which was published on Jan. 7 in the journal Cerebral Cortex.

Kaplan thinks that it's not just that the brain is presented with a moral quandary, but rather that the quandary is presented in a narrative format.

"Stories help us to organize information in a unique way," he said.

To find relevant stories, the researchers sorted through 20 million blog posts using software developed at the USC Institute for Creative Technologies.

"We wanted to know how people tell stories in their daily lives. It was kind of like finding stories in their natural habitat," said Kaplan, assistant research professor of psychology at the Brain and Creativity Institute at the USC Dornsife College of Letters, Arts and Sciences.

That 20 million was pared down to 40 stories that each contained an example of a crisis involving a potentially protected value: cheating on a spouse, having an abortion, crossing a picket line, or getting in a fight.

Those stories were translated into Mandarin Chinese and Farsi, and then read by American, Chinese and Iranian participants in their native language while their brains were scanned by fMRI. They also answered general questions about the stories while being scanned.

Stories that participants said involved values that were protected to them activated the default mode network in their brain to a greater degree. In addition, the level of activation varied from culture to culture. On average, Iranians showed the greatest level of activation in the study, while the Chinese participants showed the least.

"Stories appear to be a fundamental way in which the brain organizes information in a practical and memorable manner. It is important to understand the neural mechanisms required to do this, and this study is a step in that direction," said Antonio Damasio, senior author of the study. Damasio is co-director of the Brain and Creativity Institute, holder of the David Dornsife Chair in Neuroscience and a professor of psychology and neurology.

It's not yet clear whether a value either is or is not protected, or whether the sacredness of a value is on a sliding scale. But in a nation where political beliefs are growing more polarized and entrenched, it's important to understand what biological processes lie at the root of these values, Kaplan said.

"People will often hold political values as protected values and protected values are at the root of many political conflicts around the world, which is why they're interesting to us," he said.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/01/160107094111.htm

Been here before: How the brain builds place memories

Researchers activate previously dormant memory cells

February 4, 2016
Science Daily/Universitaet Tübingen
Neuroscientists have succeeded in activating dormant memory cells in rats. Using weak electrical impulses targeted at previously inactive cells in the hippocampus, the researchers induced the cells to recognize the exact place where the impulse had been first administered. The new study offers insight into the question of how memories are formed within our brains.

Memory is one of the most important functions of our brain. Not only does it allow us to regale our grandchildren with the exploits of our youth; it is essential for many everyday procedures. Our memory is constantly and immediately active whenever we experience a new thing. For instance, after meeting somebody only once, we still recognise them after hours or days. And even when we go somewhere for the first time -- for instance, the perfume section of a department store, a particular office in a building, or the toilet in a restaurant -- we will usually be able to find our way to the exit without a problem.

So our memory is not only constantly alert, it also constructs new recollections very quickly -- often during the first interaction. The reason for this alacrity of memory formation is the fact that for every person, every place -- and probably a lot of other concepts, too -- there are individual memory cells that are specifically assigned to that memory. One subtype of these neurons called granule cells is situated in the hippocampus, a centrally located brain area. Whenever memory concepts like "my living room" or "Angela Merkel" are activated -- e.g. by stepping into the living room or by seeing a photo of the German chancellor -- the small number of granule cells associated with that memory become activated in the form of electrical discharges. The large majority of the remaining neurons, however, remain dormant.

Up to now, the mechanisms through which individual granule cells are assigned to specific memories were not understood. The question of whether 'silent' granule cells can become activated under certain circumstances proved particularly intriguing. The Tübingen research team led by Dr. Andrea Burgalossi worked on the assumption that granule cells which receive electrical impulses can be 'un-silenced' and thus become memory cells. To confirm their hypothesis, they inserted hair-thin microelectrodes into the dentate gyrus of rats -- an area within the hippocampus which is responsible for memories of space and location -- allowing them to send weak electrical impulses to individual granule cells.

The rats were allowed to explore a simple labyrinth, and at a specific location within this labyrinth, individual granule cells were stimulated with weak electrical pulses (in the nanoampere range) via the microelectrode. The same electrode allowed the researchers to measure the subsequent activity of the stimulated cells. The result: whenever the rats arrived at the same spot within the labyrinth where the original impulse had been administered, stimulated granule cells now fired spontaneously. The electrical impulse had thus induced the individual granule cells to form a place memory.

Moreover, Dr. Burgalossi and his team found that the duration and temporal pattern of the impulses administered play a large role. The impulses formed more durable place memories when they followed the natural theta-rhythm of the brain -- a periodic increase and decrease in electrical potential which takes place roughly 4 to 12 times per second. Another finding could turn out to be of equal importance: rats that were new to the labyrinth reacted much more keenly to the induced place memory than rats that had been given the run of the labyrinth beforehand. Apparently, memory cells can be activated more easily when the brain is exposed to novel information.

These new insights into memory formation shed light on one of the most important functions of the human brain. And though there is still much to do before fundamental findings like these can offer new strategies for the treatment of brain diseases which affect memory formation (e.g. Alzheimer's disease, Parkinson, dementia), they represent an indispensable first step on the way.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/02/160204122050.htm

Scientists find brain plasticity assorted into functional networks

Experiences change brain cells differently

February 4, 2016
Science Daily/Virginia Tech
Scientists had thought that most synapses of a similar type and in a similar location in the brain behaved in a similar fashion with respect to how experience induces plasticity. In this work, scientists found dramatic differences in the plasticity response, even between neighboring synapses in response to identical activity experiences.

The brain still has a lot to learn about itself. Scientists at the Virginia Tech Carilion Research Institute have made a key finding of the striking differences in how the brain's cells can change through experience.

Their results were published this week in PLOS ONE.

"Neurons can undergo long-term changes in response to experience such as learning, emotions, or other activity," said Michael Friedlander, executive director of the Virginia Tech Carilion Research Institute. Friedlander co-authored the paper with his former graduate student and postdoctoral fellow, Ignacio Saez. "Neuroscientists have focused much of their attention on understanding the neuroplasticity of the connections between nerve cells called synapses."

Synapses, the specialized connections between neurons, work by translating an electrical signal from one neuron into a chemical signal to modify the receiving neuron. The chemical signal triggers an electrical signal in the receiving neuron, and the process continues.

Synapses may become stronger or weaker by changing efficiency of the chemical communication process in response to repeated bouts of co-activation of the two interconnected neurons. This process, called synaptic plasticity, can cause changes that persist beyond the co-activation period for mere minutes through a lifetime.

Outside experience can be internalized as a physical reorganization of the brain's synaptic communication process. This is especially important during the brain's development but also throughout life as experiences such as learning continually modify the brain's synaptic circuitry.

"Until recently, scientists had thought that most synapses of a similar type and in a similar location in the brain behaved in a similar fashion with respect to how experience induces plasticity," Friedlander said. "In our work, however, we found dramatic differences in the plasticity response, even between neighboring synapses in response to identical activity experiences."

Friedlander and Saez reported that neurons whose excitatory synapses are in a certain states of plasticity, based on previous experiences, assort themselves into groups to converge onto specific individual neurons in the developing brain.

"Individual neurons whose synapses are most likely to strengthen in response to a certain experience are more likely to connect to certain partner neurons, while those whose synapses weaken in response to a similar experience are more likely to connect to other partner neurons," Friedlander said. "The neurons whose synapses do not change at all in response to that same experience are more likely to connect to yet other partner neurons, forming a more stable but non-plastic network."

The researchers observed this like-type synaptic plasticity buddy system in a rodent model, using an isolated part of the cerebral cortex responsible for processing vision. The scientists recorded electrical activity from individual neurons after activating groups of neighboring neurons. They then compared that recording to the electrical activity elicited in response to the activation of only a single neighboring neuron. The synapses were trained by repeating the activation process, to mimic learning.

When the scientists applied a pharmacological agent to the neurons that blocked synaptic inhibition, they saw that training elicited more dramatic and varied plasticity at excitatory synapses. The plasticity responses of different groups of synapses on a given neuron were more similar when inhibition was blocked, which effectively grouped together like-type neurons by their learning responses.

"While we've known for years that neurons of similar types tend to richly interconnect, this is the first demonstration that such assortment processes apply to synaptic plasticity," Friedlander said. "Such a result has implications for enhanced learning paradigms, as well as for better understanding the dynamic network properties of the large-scale neuronal networks in the living brain."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/02/160204175640.htm

Older and younger adults surf different brain waves

Scientists discover how aging rewires our brain

February 8, 2016
Science Daily/Baycrest Centre for Geriatric Care
Cognitive scientists have found more evidence that aging brains work differently than younger brains when performing the same memory task, pointing to a potentially new direction for age-related cognitive care and exploration.

The study, led by the Rotman Research Institute at Baycrest Health Sciences, found that younger and older adults show very different brain wave patterns when performing the same memory task. The study was published online in January in the journal Neurobiology of Learning and Memory.

"We know that our brains change over time, but fully understanding how we make and recall memories as we age has been a mystery," said Renante Rondina, a University of Toronto and Rotman graduate student in the Department of Psychology and lead author of the study. "Our findings are really novel as they show distinct differences in brain activity from one generation to the next. By mapping these key differences, we may be able to identify new ways to predict, diagnose and screen for cognitive decline."

The findings show that rhythmic activity within key regions of the brain, including the hippocampus, an area that is involved with the formation and retrieval of memories, and the neocortex, the grey matter "wrapping paper" of the brain which is concerned with sight, hearing, attention, and high-level thinking, change with advanced age.

Structural magnetic resonance imaging (MRI), which measures the anatomy and structural integrity of the brain, and magnetoencephalography (MEG), which measures magnetic fields created by the brain's electrical activity, were used to track potential age-related differences as groups of younger and older adults performed a memory task. The median ages of the two groups were 24.8 and 65.9 years, respectively.

Rondina explained that brains are made up of billions of cells, which use electricity to communicate with each other. As signals are sent from one cell to the next, rhythmic patterns of electrical activity, commonly known as brain waves, are generated.

"Past studies have shown that brain waves travelling at slower speeds tend to be important for memory, while slightly faster speed brain waves play a role in our attention," said Rondina. "Other studies have looked at brain wave patterns as we process and recall memories, but our study is one of the first to look at key differences between younger and older adults' brain waves as they make and recall new memories."

While participant accuracy in the memory tasks was consistent across both groups, younger adults showed a surge in theta power (slower brain waves) that was predictive of their memory accuracy. In contrast, older adults demonstrated a rush of alpha oscillatory power (relatively faster brain waves) that was not observed in younger adults.

"It's remarkable to see how different the older participants' brain patterns are from the younger participants, while still maintaining accuracy," said Rondina. "According to the MRIs, there were minimal differences in the brain structures in the two groups, yet the brain waves were very different. With additional study, these results may lead to new, more sensitive ways of screening or diagnosing cognitive decline."

Rondina says the study's results do not immediately change diagnosis or treatment options for age-related cognitive impairments, but it will be interesting to see the long-term implications of these results, as we continue to learn how our brains change as we age.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/02/160208135447.htm

Best to sleep on it: Brain activity patterns during sleep consolidate memory

February 19, 2016
Science Daily/University of Bristol
Why does sleeping on it help? This is the question tackled by new research, which reveals how brain activity during sleep sorts through the huge number of experiences we encounter every day, filing only the important information in memory.

The new discoveries, made by researchers from Bristol's Centre for Synaptic Plasticity, provide further evidence for the benefits of a good night's sleep. This is important because the bad nights of sleep often experienced by both the healthy population, and people with schizophrenia or Alzheimer's disease, lead to impaired mental function.

The findings, published in the journal Cell Reports, and put into context in an article in Trends in Neuroscience, show that patterns of brain activity that occur during the day are replayed at fast-forward speed during sleep.

This replayed activity happens in part of the brain called the hippocampus, which is our central filing system for memories. The key new finding is that sleep replay strengthens the microscopic connections between nerve cells that are active -- a process deemed critical for consolidating memories. Therefore, by selecting which daytime activity patterns are replayed, sleep can sort and retain important information.

Lead researcher Dr Jack Mellor, from the School of Physiology, Pharmacology and Neuroscience, said: 'These findings are about the fundamental processes that occur in the brain during the consolidation of memory during sleep. It also seems that the successful replay of brain activity during sleep is dependent on the emotional state of the person when they are learning. This has major implications for how we teach and enable people to learn effectively.'
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/02/160219134813.htm

Long-term stress erodes memory

Study in mice places blame on immune system

March 1, 2016
Science Daily/Ohio State University
Sustained stress -- such as that experienced in bad marriages or when working for a beastly boss -- erodes memory, and the immune system plays a key role, according to a new study.

The work in mice could one day lead to treatment for repeated, long-term mental assault such as that sustained by bullying victims, soldiers and those who report to beastly bosses, the researchers say.

"This is chronic stress. It's not just the stress of giving a talk or meeting someone new," said lead researcher Jonathan Godbout, associate professor of neuroscience at Ohio State.

This is the first study of its kind to establish the relationship between short-term memory and prolonged stress. In the case of the mice, that meant repeat visits from a larger, nasty intruder mouse.

Mice that were repeatedly exposed to the aggressive intruder had a hard time recalling where the escape hole was in a maze they'd mastered prior to the stressful period.

"The stressed mice didn't recall it. The mice that weren't stressed, they really remembered it," Godbout said.

They also had measurable changes in their brains, including evidence of inflammation brought on by the immune system's response to the outside pressure. This was associated with the presence of immune cells, called macrophages, in the brain of the stressed mice.

The research team was able to pin the short-term memory loss on the inflammation, and on the immune system.

Their work, which appears in The Journal of Neuroscience, builds on previous research substantiating the connections between chronic stress and lasting anxiety.

The impact on memory and confirmation that the brain inflammation is caused by the immune system are important new discoveries, Godbout said.

"It's possible we could identify targets that we can treat pharmacologically or behaviorally," he said.

It could be that there are ways to interrupt the inflammation, said John Sheridan, who worked on the study and is associate director of Ohio State's Institute for Behavioral Medicine Research.

The mice used in the study are exposed to repeated social defeat -- basically dominance by an alpha mouse -- that aims to mimic chronic psychosocial stress experienced by humans.

Researchers at Ohio State seek to uncover the secrets behind stress and cognitive and mood problems with a long-range goal of finding ways to help those who are anxious, depressed and suffer from lasting problems, including post-traumatic stress disorder.

This new research focused on the hippocampus, a hub of memory and emotional response.

The researchers found that the stressed mice had trouble with spatial memory that resolved within 28 days. They found that the mice displayed social avoidance, which measures depressive-like behavior, that continued after four weeks of monitoring.

And they were able to measure deficits in the development of new neurons 10 days and 28 days after the prolonged stress ended.

When they gave the mice a chemical that inhibited inflammation, neither the brain-cell problem nor the depressive symptoms went away. But the memory loss and inflammatory macrophages did disappear.

And that led them to conclude that the post-stress memory trouble is directly linked to inflammation -- and the immune system -- rather than to other damage to the brain. That type of information can pave the way for immune-based treatments, Godbout said.

"Stress releases immune cells from the bone marrow and those cells can traffic to brain areas associated with neuronal activation in response to stress," Sheridan said. "They're being called to the brain, to the center of memory."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/03/160301173947.htm

Blueberries, the well-known 'super fruit,' could help fight Alzheimer's

March 14, 2016
Science Daily/Science Daily/American Chemical Society
The blueberry, already labeled a 'super fruit' for its power to potentially lower the risk of heart disease and cancer, also could be another weapon in the war against Alzheimer's disease. New research being presented today further bolsters this idea, which is being tested by many teams. The fruit is loaded with healthful antioxidants, and these substances could help prevent the devastating effects of this increasingly common form of dementia, scientists report.

The researchers present their work today at the 251st National Meeting & Exposition of the American Chemical Society (ACS).

"Our new findings corroborate those of previous animal studies and preliminary human studies, adding further support to the notion that blueberries can have a real benefit in improving memory and cognitive function in some older adults," says Robert Krikorian, Ph.D., leader of the research team. He adds that blueberries' beneficial effects could be due to flavonoids called anthocyanins, which have been shown to improve animals' cognition.

Currently 5.3 million people suffer from Alzheimer's disease. But that number is expected to increase, Krikorian notes, as the U.S. population ages. By 2025, the number of Americans with this degenerative disorder could rise 40 percent to more than 7 million, and it could almost triple by 2050, according to the Alzheimer's Association.

In an effort to find ways to slow down this alarming trend, Krikorian and colleagues at University of Cincinnati Academic Health Center conducted two human studies to follow up on earlier clinical trials.

One study involved 47 adults aged 68 and older, who had mild cognitive impairment, a risk condition for Alzheimer's disease. The researchers gave them either freeze-dried blueberry powder, which is equivalent to a cup of berries, or a placebo powder once a day for 16 weeks.

"There was improvement in cognitive performance and brain function in those who had the blueberry powder compared with those who took the placebo," Krikorian says. "The blueberry group demonstrated improved memory and improved access to words and concepts." The team also conducted functional magnetic resonance imaging (fMRI), which showed increased brain activity in those who ingested the blueberry powder.

The second study included 94 people aged 62 to 80, who were divided into four groups. The participants didn't have objectively measured cognitive issues, but they subjectively felt their memories were declining. The groups received blueberry powder, fish oil, fish oil and powder or placebo.

"The results were not as robust as with the first study," Krikorian explained. "Cognition was somewhat better for those with powder or fish oil separately, but there was little improvement with memory." Also, fMRI results also were not as striking for those receiving blueberry powder. He says that the effect may have been smaller in this case because these participants had less severe issues when they entered the study.

Krikorian said the two studies indicate that blueberries may be more effective in treating patients with cognitive impairments, but may not show measurable benefit for those with minor memory issues or who have not yet developed cognitive problems.

In the future, the team plans to conduct a blueberry study with a younger group of people, aged 50 to 65. The group would include people at risk of developing Alzheimer's, such as those who are obese, have high blood pressure or high cholesterol. This work could help the researchers determine if blueberries could help prevent the onset of Alzheimer's symptoms.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/03/160314084821.htm

Tooth loss increases the risk of diminished cognitive function

Systematic review shows association between tooth loss, reduced cognitive function in adults

March 23, 2016
Science Daily/Science Daily/International & American Associations for Dental Research
The International and American Associations for Dental Research (IADR/AADR) have published an article titled "Tooth Loss Increases the Risk of Diminished Cognitive Function: A Systematic Review and Meta-analysis" in the OnlineFirst portion of the JDR Clinical & Translational Research. In it, Cerutti-Kopplin et al systematically assessed the association between oral health and cognitive function in adult populations.

The increase of cognitive impairment and its pathologic correlates, such as dementia and Alzheimer's disease, in aging populations is progressing worldwide and creating a significant burden on health systems. Better insight into the nature and extent of the association between oral health and cognitive function is of great importance since it could lead to preventive interventions for cognitive performance. Therefore, the objective of this review was to systematically examine if tooth loss leads to cognitive impairment and its most prevalent pathologic correlate (dementia).

Eligible study reports were identified by searching the MEDLINE (via Ovoid), EMBASE, PsycoINFO and Cochrane Library databases. Pooled hazard ratios with 95 percent confidence intervals were calculated with a random effects model. From 1,251 identified articles, 10 were included in the systematic review and eight in the meta-analysis. Random effects analysis showed, with statistically low heterogeneity, that individuals with less than 20 teeth were at a 20 percent higher risk for developing cognitive decline (hazard ratios equal 1.26, 95 percent confidence intervals equal 1.14 to 1.40) and dementia (hazard ratios equal 1.22, 95 percent confidence intervals equal 1.04 to 1.43) than those with greater than or equal to 20 teeth.

Based on the published literature, the results of this study show that the risk for cognitive impairment and dementia increases with loss of teeth. This information suggests that oral health strategies aimed to preserve teeth may be important in reducing risk of systemic disease.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/03/160323152025.htm

Wisdom is a matter of both heart and mind

April 7, 2016
Science Daily/University of Waterloo
The fluctuations of your heartbeat may affect your wisdom, according to new research. The study suggests that heart rate variation and thinking process work together to enable wise reasoning about complex social issue

The study suggests that heart rate variation and thinking process work together to enable wise reasoning about complex social issues. The work by Igor Grossmann, professor of psychology at Waterloo, and colleagues based at the Australian Catholic University, appears in the online journal Frontiers in Behavioral Neuroscience.

Their study breaks new ground in wisdom research by identifying conditions under which psychophysiology impacts wise judgment.

"Our research shows that wise reasoning is not exclusively a function of the mind and cognitive ability," says Prof. Grossmann. "We found that people who have greater heart rate variability and who are able to think about social problems from a distanced viewpoint demonstrate a greater capacity for wise reasoning."

The study extends previous work on cognitive underpinnings of wise judgment to include consideration how the heart's functioning impacts the mind.

A growing consensus among philosophers and cognitive scientists defines wise judgment to include the ability to recognize the limits of one's knowledge, to be aware of the varied contexts of life and how they may unfold over time, to acknowledge others' points of view, and to seek reconciliation of opposing viewpoints.

The new study is the first to show that the physiology of the heart, specifically the variability of heart rate during low physical activity, is related to less biased, wiser judgment.

Human heart rate tends to fluctuate, even during steady-state conditions, such as while a person is sitting. Heart rate variability refers to the variation in the time interval between heartbeats and is related to the nervous system's control of organ functions.

The researchers found that people with more varied heart rates were able to reason in a wiser, less biased fashion about societal problems when they were instructed to reflect on a social issue from a third-person perspective. But, when the study's participants were instructed to reason about the issue from a first-person perspective, no relationship between heart rate and wiser judgment emerged.

"We already knew that people with greater variation in their heart rate show superior performance in the brain's executive functioning such as working memory," says Prof. Grossmann. "However, that does not necessarily mean these people are wiser -- in fact, some people may use their cognitive skills to make unwise decisions. To channel their cognitive abilities for wiser judgment, people with greater heart rate variability first need to overcome their egocentric viewpoints."

The study opens the door for further exploration of wise judgment at the intersection of physiological and cognitive research.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/04/160407221449.htm

How the brain consolidates memory during deep sleep

Using a computational model, study explains how hippocampus influences synaptic connections in cortex

April 14, 2016
Science Daily/University of California - Riverside
How long-term memory is formed is not well understood, and remains a central question of inquiry in neuroscience. Now researchers report they may have an answer to this question
https://images.sciencedaily.com/2016/04/160414214830_1_540x360.jpg
A UC Riverside study explains how the hippocampus influences synaptic connections in the cortex during deep sleep.
Credit: © paylessimages / Fotolia

Neuroscientists at the University of California, Riverside report in the Journal of Neuroscience that they now may have an answer to this question. Their study provides for the first time a mechanistic explanation for how deep sleep (also called slow-wave sleep) may be promoting the consolidation of recent memories.

During sleep, human and animal brains are primarily decoupled from sensory input. Nevertheless, the brain remains highly active, showing electrical activity in the form of sharp-wave ripples in the hippocampus (a small region of the brain that forms part of the limbic system) and large-amplitude slow oscillations in the cortex (the outer layer of the cerebrum), reflecting alternating periods of active and silent states of cortical neurons during deep sleep. Traces of episodic memory acquired during wakefulness and initially stored in the hippocampus are progressively transferred to the cortex as long-term memory during sleep.

Using a computational model, the UC Riverside researchers provide a link between electrical activity in the brain during deep sleep and synaptic connections between neurons. They show that patterns of slow oscillations in the cortex, which their model spontaneously generates, are influenced by the hippocampal sharp-wave ripples and that these patterns of slow oscillations determine synaptic changes in the cortex. (Change in synaptic strength is widely believed to underlie learning and memory storage in the brain.) The model shows that the synaptic changes, in turn, affect the patterns of slow oscillations, promoting a kind of reinforcement and replay of specific firing sequences of the cortical neurons -- representing a replay of specific memory.

"These patterns of slow oscillations remain even without further input from the hippocampus," said Yina Wei, a postdoctoral researcher and the first author of the research paper. "We interpret these results as a mechanistic explanation for the consolidation of specific memories during deep sleep, whereby the memory traces are formed in the cortex and become independent of the hippocampus."

Study results appear in the Journal of Neuroscience.

Wei explained that according to the biologically realistic network model the researchers used, input from the hippocampus reaches the cortex during deep sleep and influences how the slow oscillations are initiated and propagated in the cortical network.

"Input from the hippocampus -- the sharp-wave ripples -- determines the spatial and temporal pattern of these slow oscillations," she said. "By influencing the nature of these oscillations, this hippocampal input activates selective memories during deep sleep and causes a replay of specific memories. During such memory replay, the corresponding synapses are strengthened for long-term storage in the cortex. These results suggest the importance of the hippocampal sharp-wave ripple events in transferring memory information to the cortex."

Normal sleep, during which brain activity remains high, is made up of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. NREM and REM sleep alternate in each of the 4-5 cycles during an eight-hour sleep period. Each cycle consists of NREM sleep followed by REM sleep, and roughly lasts 90-110 minutes. NREM sleep has three stages, Stage 3 being deep sleep. Deep sleep, which makes up at least 20 percent of a person's total sleep time, occurs mostly in the first third of the night.

"In our model, even weak and spatially localized input from the hippocampus influenced the spatiotemporal pattern of slow oscillations and led to a persistent change of synaptic efficacy between neurons," Wei said. "Further, our model makes predictions that can be tested experimentally, including specific interventions to suppress or augment memory consolidation processes."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/04/160414214830.htm

Holistic approach to mealtimes could help dementia sufferers

May 4, 2016
Science Daily/University of East Anglia
Eating together could help people with dementia avoid dehydration and malnutrition, new research shows. Researchers looked at mealtime interventions including changing the color of the plate, increasing exercise, waitress service, playing different types of music, singing, doing tai-chi, and boosting the social aspect of eating. They found that eating family-style meals with care givers, playing music, and engaging with multisensory exercise could boost nutrition, hydration and quality of life.

Findings published reveal that while no interventions were unequivocally successful, promising approaches focused on a holistic approach to mealtimes.

The team found that eating family-style meals with care givers, playing music, and engaging with multisensory exercise -- could all help boost nutrition, hydration and quality of life among people with dementia.

Lead researcher Dr Lee Hooper, from UEA's Norwich Medical School, said: "The risk of dehydration and malnutrition are high in older people, but even higher in those with dementia.

"Malnutrition is associated with poor quality of life so understanding how to help people eat and drink well is very important in supporting health and quality of life for people with dementia.

"We wanted to find out what families or carers can do to help people with dementia eat well and drink enough."

The team systematically reviewed research from around the world and assessed the effectiveness of 56 interventions which all aimed to improve, maintain, or facilitate food or drink intake among more than 2,200 people with dementia.

Interventions tested included changing the colour of the plate, increasing exercise, waitress service, playing different types of music, singing, doing tai-chi, creating a home-like eating environment, providing nutrition supplements, and boosting the social aspect of eating.

They also looked at whether better education and training for formal or informal care-givers could help, as well as behavioural interventions -- such as giving encouragement for eating.

The research team assessed whether these interventions improved hydration status and body weight, and whether the intervention helped older people to enjoy the experience of eating or drinking, and improved their quality of life.

Dr Hooper said: "We found a number of promising interventions -- including eating meals with care-givers, having family-style meals, facilitating social interaction during meals, longer mealtimes, playing soothing mealtime music, doing multisensory exercise and providing constantly accessible snacks.

"Providing education and support for formal and informal care-givers were also promising.

"But one of the problems of this research is that many of the studies we looked at were too small to draw any firm conclusions -- so no interventions should be clearly ruled in or out and more research in this area is needed.

"It is probably not just what people with dementia eat and drink that is important for their nutritional wellbeing and quality of life -- but a holistic mix of where they eat and drink, the atmosphere, physical and social support offered, the understanding of formal care-givers, and levels of physical activity enjoyed."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/05/160504121808.htm

Rapid eye movement sleep: Keystone of memory formation

May 13, 2016
Science Daily/McGill University
For decades, scientists have fiercely debated whether rapid eye movement sleep -- the phase where dreams appear -- is directly involved in memory formation. Now, a study provides evidence that REM sleep does, indeed, play this role -- at least in mice.
https://images.sciencedaily.com/2016/05/160513130241_1_540x360.jpg
Dreaming. REM sleep is understood to be a critical component of sleep in all mammals, including humans.
Credit: © Anton Maltsev / Fotolia

Now, a study published in Science by researchers at the Douglas Mental Health University Institute (McGill University) and the University of Bern provides evidence that REM sleep does, indeed, play this role -- at least in mice.

"We already knew that newly acquired information is stored into different types of memories, spatial or emotional, before being consolidated or integrated," says Sylvain Williams, a researcher and professor of psychiatry at McGill.

"How the brain performs this process has remained unclear -- until now. We were able to prove for the first time that REM sleep is indeed critical for normal spatial memory formation in mice," explains Williams, whose team is also part of the CIUSSS de l'Ouest-de-l'Île-de-Montréal research network. Williams co-authored the study with Antoine Adamantidis, a researcher at the University of Bern's Department of Clinical Research and at the Sleep Wake Epilepsy Center of the Bern University Hospital.

A dream quest

Hundreds of previous studies have tried unsuccessfully to isolate neural activity during REM sleep using traditional experimental methods. In this new study, the researchers used optogenetics, a recently developed technology that enables scientists to target precisely a population of neurons and control its activity by light.

"We chose to target neurons that regulate the activity of the hippocampus, a structure that is critical for memory formation during wakefulness and is known as the 'GPS system' of the brain," Williams says.

To test the long-term spatial memory of mice, the scientists trained the rodents to spot a new object placed in a controlled environment where two objects of similar shape and volume stand. Spontaneously, mice spend more time exploring a novel object than a familiar one, showing their use of learning and recall. When these mice were in REM sleep, however, the researchers used light pulses to turn off their memory-associated neurons to determine if it affects their memory consolidation. The next day, the same rodents did not succeed the spatial memory task learned on the previous day. Compared to the control group, their memory seemed erased, or at least impaired.

"Silencing the same neurons for similar durations outside REM episodes had no effect on memory. This indicates that neuronal activity specifically during REM sleep is required for normal memory consolidation," says the study's lead author Richard Boyce, a PhD student who, ironically, often stayed up all night while performing the experiments.

Implications for brain disease

REM sleep is understood to be a critical component of sleep in all mammals, including humans. Poor sleep-quality is increasingly associated with the onset of various brain disorders such as Alzheimer's and Parkinson's disease.

In particular, REM sleep is often significantly perturbed in Alzheimer's diseases (AD), and results from this study suggest that disruption of REM sleep may contribute directly to memory impairments observed in AD, the researchers say.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/05/160513130241.htm

Brain picks up the beat of music automatically

May 26, 2016
Science Daily/University of Amsterdam
A sense of rhythm is a uniquely human characteristic. Music cognition scientists discovered that the sense of rhythm – also known as the beat – is so fundamental to humans that we recognize patterns in music even without paying any attention or receiving any training.

What most people call the sense of rhythm -- the mechanism that enables us to clap along or dance to music -- is an intangible ability that is exclusive to human beings. For example, imagine a barrel before it is placed inside a barrel organ. On the barrel, you can see exactly which tones will be played and for how long they will be audible. However, the regularity of the rhythm cannot be read on the barrel. This rhythm exists only in our heads, where our brain recognises patterns in the sounds. This helps us to predict the music, enabling us to synchronise our actions with it, i.e. dancing, clapping, singing or playing the violin.

Swaying back and forth

Human beings are the only species that recognise these patterns and scientists suspect that an evolutionary development is at the root of it. Music can work as a social lubricant within a community and a sense of rhythm enables us to make music with others or sway back and forth on the bleachers of a football stadium.

For five years, Fleur Bouwer plumbed the depths of the human sense of rhythm in order to map out the fundamental brain processes that lie at its roots. She discovered that both training -- i.e. music lessons -- and concentration -- i.e. paying attention to the music -- are unnecessary in recognising rhythm. Even the brains of untrained listeners can recognise the rhythm of a piece of music, even when performing a completely different task.

However, the PhD candidate would like to dispel one misunderstanding: the fact that nearly everyone is capable of recognising musical rhythm does not mean that everybody can dance to that rhythm. 'This requires more complex motor skills on top of the ability to recognise the rhythm, and unfortunately these skills are not as universal to humans as the sense of rhythm.'

Parkinson's disease

Although training and attention are not necessary for picking up rhythm, they do help. Professional musicians have been shown to be better than normal people at predicting notes in a rhythm based on the rhythm they recognised in an excerpt of music. This ability was its strongest when the musicians were concentrating hard. Bouwer: 'My results show that, to a certain extent, the sense of rhythm is a fundamental brain process that develops unconsciously. However, training may well help you to make predictions based on the rhythm. This is useful when playing music or dancing.'

Bouwer hopes that knowledge of musical perception can ultimately be used to help people. 'The brain scanner displays activity in the motor networks when people listen to music with a clearly discernible rhythm. I find that particularly interesting. Maybe we can eventually use this relationship between musical experience and the motor system to help people with motor-system disorders such as Parkinson's disease. However, before we explore this possibility, we must gain a better understanding of the fundamental processes. My research contributes to this.'
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/05/160526125017.htm

Mimicking deep sleep brain activity improves memory

May 26, 2016
Science Daily/RIKEN
It is not surprising that a good night's sleep improves our ability to remember what we learned during the day. Now, researchers have discovered a brain circuit that governs how certain memories are consolidated in the brain during sleep. The study shows how experimentally manipulating the identified neural connection during non-REM sleep (deep sleep) can prevent or enhance memory retention in mice.
https://images.sciencedaily.com/2016/05/160526151749_1_540x360.jpg
In this image, a mouse explores a room with a textured floor.
Credit: RIKEN

The team led by Masanori Murayama studied the long-known phenomenon of memory consolidation during sleep by building off their recent study on tactile perception in which they found that perceiving texture requires signaling within a neural circuit from higher-level motor-related brain regions back to lower-level touch-related sensory areas. They reasoned that the same "top-down" pathway might also consolidate memories of textures. Explains Murayama, "There is a long standing hypothesis that top-down input is crucial for memory consolidation and that during sleep, neurons in sensory regions activated during the initial experience can "reactivate" by unknown pathways. We found such reactivation of the top-down pathway is critical for mice to encode memories of their tactile experiences."

The researchers developed a task to assess memory retention that relies on the natural inclination of mice to spend more time investigating new items in their environment. First they allowed mice to explore objects in two rooms with smooth floors, then they changed one of the smooth floors to a textured floor and again allowed the mice to explore. With normal sleep, mice spent more time exploring the room with the textured floor, showing that they remembered the smooth room and were less interested in it. Typically, this behavior was observed as long as the second exploration occurred within two days.

To examine whether the top down circuit was responsible for memory consolidation during sleep, they manipulated the mice in several ways. First, they showed that sleep deprivation immediately following the first tactile experience caused mice to explore the textured room less often on the second exploration, indicating that they did not remember the smooth room. Next, they inactivated the top-down neural pathway during non-REM sleep shortly after the first exploration and found that during the second exploration, mice performed as if they had been sleep deprived. Silencing the top-down pathway when mice were awake or during non-REM sleep at later times had no effect on performance, indicating that memory consolidation happened in the first bout of non-REM sleep after the experience.

The importance of top-down circuit activation in non-REM sleep suggested that memory consolidation might involve synchronous slow wave brain activity between the two brain regions that is characteristic of non-REM sleep. To test this, they artificially applied synchronous or asynchronous activity in the higher and lower regions of the circuit during non-REM sleep after the first tactile experience. Mice with asynchronous activation were unable to consolidate memories, but synchronous activation allowed them to retain a strong memory of the smooth floor for at least 4 days or twice as long as normal. The synchronous treatment even rescued the typical lack of memory retention in sleep-deprived mice.

"Our findings on sleep deprivation are particularly interesting from a clinical perspective," says Murayama. "Patients who suffer from sleep disorders often have impaired memory functions. Our findings suggest a route to therapy using transcortical magnetic or direct-current stimulation to top down cortical pathways to reactivate sleep-deprived neurons during non-REM sleep. Our next step is to test this in mouse models of sleep-disorders.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/05/160526151749.htm

Senior moments explained: Older adults have weaker clutter control

June 14, 2016
Science Daily/Georgia Institute of Technology
Older people struggle to remember important details because their brains can't resist the irrelevant 'stuff' they soak up subconsciously. As a result, they tend to be less confident in their memories, say researchers.
https://images.sciencedaily.com/2016/06/160614155726_1_540x360.jpg
An assistant professor in the School of Psychology uses the functional MRI scanner at the Georgia State/Georgia Tech Center for Advanced Brain Imaging to measure activity from thousands of neurons in the brain at the same time while subjects try to retrieve episodic memories.
Credit: © Helder Almeida / Fotolia

Researchers looked at brain activity from EEG sensors and saw that older participants wandered into a brief "mental time travel" when trying to recall details. This journey into their subconscious veered them into a cluttered space that was filled with both relevant and irrelevant information. This clutter led to less confidence, even when their recollections were correct. Cluttering of the brain is one reason older people are more susceptible to manipulation, the researchers say. The study appears online in the journal Neuropsychologia.

Researchers showed older adults (60 years and up) and college students a series of pictures of everyday objects while EEG sensors were connected to their heads. Each photo was accompanied by a color and scene (e.g., living room). Participants were told to focus on one and ignore the other. An hour later, they were asked if the object was new or old, and if it matched the color and the scene.

Neither age group was very good at recalling what they were told to ignore. Both did well remembering the object and what they were supposed to focus on.

"But when we asked if they were sure, older people backed off their answers a bit. They weren't as sure," said Audrey Duarte, the associate professor of psychology who led the Georgia Tech study.

She and the researchers noticed differences in brain activity between the young and old. Older adults' brains spent more time and effort trying to reconstruct their memories.

"While trying to remember, their brains would spend more time going back in time in an attempt to piece together what was previously seen," she said. "But not just what they were focused on -- some of what they were told to ignore got stuck in their minds."

Duarte uses a cocktail party as an example. Two older people are talking to each other. And even though they're only concentrating on the conversation, their brains absorb the other noise in the room.

"When it's time to remember the conversation, they may struggle a bit to recall some details. That's because their brains are also trying to decipher the other noises," she said. "What music was playing? What was the couple next to them saying? That extra stuff shouldn't be in their memories at all, but it is. And it negatively impacts their ability to clearly remember the conversation."

Younger people were quicker to recall details and used less brain power. The irrelevant information was never stored in the first place, which kept their memories relatively clutter-free. And that's why they were more confident than the older participants when remembering relevant details.

A lack of confidence, Duarte said, can lead to manipulation.

"If someone tells you that you should remember it one way, you can be more easily persuaded if you lack confidence," she said. "This memory clutter that's causing low confidence could be a reason why older adults are often victims of financial scams, which typically occur when someone tries to trick them about prior conversations that didn't take place at all."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/06/160614155726.htm