HealthMedicine 12

Dreams activate the brain in a similar way to real actions

October 28, 2011

Science Daily/Max-Planck-Gesellschaft

The ability to dream is a fascinating aspect of the human mind. However, how the images and emotions that we experience so intensively when we dream form in our heads remains a mystery. Up to now it has not been possible to measure dream content. Scientists in Germany have now succeeded, for the first time, in analyzing the activity of the brain during dreaming.

 

They were able to do this with the help of lucid dreamers, i.e. people who become aware of their dreaming state and are able to alter the content of their dreams. The scientists measured that the brain activity during the dreamed motion matched the one observed during a real executed movement in a state of wakefulness.

 

The coincidence of the brain activity measured during dreaming and the conscious action shows that dream content can be measured. "With this combination of sleep EEGs, imaging methods and lucid dreamers, we can measure not only simple movements during sleep but also the activity patterns in the brain during visual dream perceptions," says Martin Dresler, a researcher at the Max Planck Institute for Psychiatry.

http://www.sciencedaily.com/releases/2011/10/111028113626.htm

 

How lonely you are may impact how well you sleep

November 2, 2011

Science Daily/American Academy of Sleep Medicine

Study of adults in tight-knit South Dakota community shows lonely feelings associated with compromised sleep -- that is, the stronger the loneliness, the more disruptions during the night, with potentially negative consequences on wellness. Results agree with 2002 study of college students, indicating that individuals young and old, in big towns and small, need to feel secure in their social setting to get a healthy night's rest.

 

"It's not just a product of very lonely individuals having poor sleep. The relationship between loneliness and restless sleep appears to operate across the range of perceived connectedness," said lead author Lianne Kurina, PhD, of the Department of Health Studies at the University of Chicago.

 

"Loneliness has been associated with adverse effects on health," Kurina said. "We wanted to explore one potential pathway for this, the theory that sleep -- a key behavior to staying healthy -- could be compromised by feelings of loneliness. What we found was that loneliness does not appear to change the total amount of sleep in individuals, but awakens them more times during the night."

 

"Whether you're a young student at a major university or an older adult living in a rural community, we may all be dependent on feeling secure in our social environment in order to sleep soundly," Kurina said. "The results from these studies could further our understanding of how social and psychological factors 'get under the skin' and affect health."

http://www.sciencedaily.com/releases/2011/11/111101095302.htm

Cancer-related Fatigue Reviewed

June 10, 2007
Science Daily/University of Rochester Medical Center
Scientists offer an in-depth examination of cancer-related fatigue, with hope that a better understanding of the topic will prompt new research and treatment.

In a special publication sent to thousands of oncologists nationwide this month, University of Rochester Medical Center scientists offer an in-depth examination of cancer-related fatigue, with hope that a better understanding of the topic will prompt new research and treatment.

Virtually all cancer patients complain of some degree of persistent fatigue. Coping with this challenging side effect is critical to surviving cancer, especially since many people desire to work, raise children, run a household, or engage in recreation throughout their treatments, said Joseph Roscoe, Ph.D., a co-author and research associate professor of Oncology at the University's James P. Wilmot Cancer Center.

"It used to be that fatigue was viewed as an inevitable part of sickness," said Roscoe, a cancer survivor. "Now we know better, and there's a great deal of ongoing research about what causes fatigue and how it can be managed. For some people, fatigue is so debilitating that they want to stop their cancer treatments, which is why it is particularly important to find ways to address this problem."

During his own bout with cancer fatigue, Roscoe recalled feeling "jet lagged all the time." But rest or sleep does not alleviate cancer fatigue, and it often persists for months. In some studies, patients report more stress from fatigue than from pain, depression or nausea.
Unfortunately, no one has turned up a quick fix. "Exercise is looking very promising and one psychostimulant drug, modafinil, is being studied as a potential new treatment," Roscoe said. "But nothing yet has clearly demonstrated the ability to relieve cancer-related fatigue."

The following is a snapshot of what is reviewed in the journal:

-- Scale of the problem. Of the 1.3 million Americans diagnosed with cancer in 2005, 95 percent of the people scheduled to receive chemotherapy or radiation expected to experience fatigue. Studies show the frequency of actual fatigue during chemo ranges from 70 to 100 percent; likewise, 90 percent of patients who receive radiation therapy report fatigue. Also, up to 40 percent of patients report unusual fatigue upon diagnosis, a sign that fatigue is an early symptom of malignancy as well as a consequence of treatment.

-- Underlying causes. Cancer fatigue disrupts several interrelated systems: physiological, biochemical, psychological. The effect varies among individuals and also during different phases of treatment. It likely involves changes in the endocrine system, circadian rhythms, metabolism, cytokines and seratonin production. Predisposing factors must be understood before researchers can develop useful prevention or treatment strategies.

-- Measurement of a subjective symptom. More than 20 different assessments are used to diagnose fatigue, from single-question scales to multidimensional measurements of a patient's physical, emotional and cognitive functioning. Most patients can easily rate their fatigue on a scale from 0 to 10, researchers said. However, it is important for physicians to distinguish cancer fatigue from other ailments such as depression, and treat accordingly.

-- Fatigue and cancer-related sleep disorders. Approximately 25 to 50 percent of all prescriptions that doctors write for cancer patients are for hypnotics. Studies show that sleep disturbances are more severe in the most fatigued patients, suggesting a reciprocal relationship between these two distinct conditions.

-- Drug remedies. The first step to managing cancer fatigue is to treat conditions that may contribute to it, such as anemia, pain or depression. Studies show that anemia medications alleviate cancer fatigue to some degree. Other classes of drugs called psychostimulants have shown promise in open-label trials. Further research is needed.

-- Non-drug remedies. A growing body of evidence shows that exercise and support groups help people with cancer fatigue the most. Additional studies into nutrition therapy, yoga, mindfulness stress reduction, and polarity therapy also show promise. Many people with cancer already use non-drug behavioral therapies on their own, researchers said, but it's important that the scientific community continue to fund and study these interventions.
http://www.sciencedaily.com/releases/2007/06/070607171151.htm

 

Sleep loss linked to psychiatric disorders


22 October 2007
Science Daily/UC Berkeley
It has long been assumed that sleep deprivation can play havoc with our emotions. This is notably apparent in soldiers in combat zones, medical residents and even new parents. Now there's a neurological basis for this theory, according to new research from the University of California, Berkeley, and Harvard Medical School.

In the first neural investigation into what happens to the emotional brain without sleep, results from a brain imaging study suggest that while a good night's rest can regulate your mood and help you cope with the next day's emotional challenges, sleep deprivation does the opposite by excessively boosting the part of the brain most closely connected to depression, anxiety and other psychiatric disorders.

"It's almost as though, without sleep, the brain had reverted back to more primitive patterns of activity, in that it was unable to put emotional experiences into context and produce controlled, appropriate responses," said Matthew Walker, director of UC Berkeley's Sleep and Neuroimaging Laboratory and senior author of the study, which will be published today (Monday, Oct. 22) in the journal Current Biology.
http://berkeley.edu/news/media/releases/2007/10/22_sleeploss.shtml

 

Lack Of Deep Sleep May Increase Risk Of Type 2 Diabetes

Jan. 2, 2008

Science Daily/University of Chicago Medical Center

Suppression of slow-wave sleep in healthy young adults significantly decreases their ability to regulate blood-sugar levels and increases the risk of type 2 diabetes, report researchers at the University of Chicago Medical Center.

Deep sleep, also called "slow-wave sleep," is thought to be the most restorative sleep stage, but its significance for physical well-being has not been demonstrated. This study found that after only three nights of selective slow-wave sleep suppression, young healthy subjects became less sensitive to insulin. Although they needed more insulin to dispose of the same amount of glucose, their insulin secretion did not increase to compensate for the reduced sensitivity, resulting in reduced tolerance to glucose and increased risk for type 2 diabetes. The decrease in insulin sensitivity was comparable to that caused by gaining 20 to 30 pounds.

http://www.sciencedaily.com/releases/2008/01/080101093903.htm

 

Bladder-Brain Link May Point To Better Treatments For Problems In Sleep

July 31, 2008 —
Science Daily/Children's Hospital of Philadelphia
Bladder problems may leave a mark on the brain, by changing patterns of brain activity, possibly contributing to disrupted sleep and problems with attention. For one in six Americans who have overactive bladder, the involuntary bladder contractions that often trigger more frequent urges to urinate, such mind-body connections may be of more than academic interest.

"We often tend to focus on just one organ, but here we see how an abnormal organ affects the whole organism," said behavioral scientist Rita J. Valentino, Ph.D., of The Children's Hospital of Philadelphia, who led the research describing how an overactive bladder altered nervous system activity in animals.

The study appeared in the July 21 online edition of the Proceedings of the National Academy of Sciences.

Overactive bladder, while it occurs in a variety of conditions in both adults and children, is especially prevalent among elderly men, in whom an enlarged prostate gland partially obstructs the flow of urine and makes bladder muscles contract involuntarily. Valentino's research team mimicked the condition in an animal model by surgically constricting the outlet of urine from rats' bladders.

Building on their previous investigations of the neural circuits between the bladder and the brain, the researchers found that two small brain structures, the Barrington's nucleus and the locus ceruleus, developed abnormal activity as a result of the bladder obstruction. In particular, the locus ceruleus showed persistently high activity, and this resulted in an abnormal electroencephalogram (EEG) recorded from the cortex, the broad mass of the brain that governs higher-level functions. In people, abnormally high activity in the cortex may result in disordered sleep, anxiety and difficulty in concentrating.

Valentino said further studies are necessary to analyze the direct connections between heightened brain activity and specific behaviors, but added that the brain circuits involving the locus ceruleus might be a useful target for drugs to improve attention and sleep patterns in patients with bladder dysfunctions.

Furthermore, she added, in addition to overactive bladder, other visceral diseases, such as irritable bowel disorder, may also affect the same neural circuitry, with similar neurobehavioral consequences.
http://www.sciencedaily.com/releases/2008/07/080729133529.htm

 

Seasonal Affective Disorder May Be Linked To Genetic Mutation

Nov. 4, 2008 —
Science Daily/University of Virginia
With the days shortening toward winter, many people will begin to experience the winter blahs. For some, the effect can be devastating.

About 6 percent of the U.S. population suffers from seasonal affective disorder, or SAD, a sometimes-debilitating depression that begins in the fall and continues through winter. Sufferers may even find it difficult to get out of bed in the morning.

Ignacio Provencio discusses Seasonal Affective Disorder

 The disorder, which is not well understood, is often treated with "light therapy," where a SAD patient spends time each morning before a bank of bright lights in an effort to trick the brain into believing that the days are not so short or dim.

A new study indicates that SAD may be linked to a genetic mutation in the eye that makes a SAD patient less sensitive to light.

"These individuals may require brighter light levels to maintain normal functioning during the winter months," said Ignacio Provencio, a University of Virginia biology professor who studies the genetics of the body's biological clock, or circadian rhythms.

Provencio and his colleagues have discovered that melanopsin, a photopigment gene in the eye, may play a role in causing SAD in people with a recently discovered mutation.

"We believe that the mutation could contribute to increasing the amount of light needed for normal functioning during winter for people with SAD," Provencio said. "Lack of adequate light may be a trigger for SAD, but not the only explanation for the disorder."

The findings are published in the online edition of the Journal of Affective Disorders, and will appear later in the print version.

The study was conducted with several other institutions, including the National Institute of Mental Health. It involved220 participants, 130of whom had been diagnosed with SAD and 90 participants with no history of mental illness.

Using a genetics test, the study authors found that seven of the 220 participants carried two copies of the mutation that may be a factor in causing SAD, and, strikingly, all seven belonged to the SAD group.

"While a person diagnosed with SAD does not necessarily carry the melanopsin mutation, what we found strongly indicates that people who carry the mutation could very well be diagnosed with SAD," Provencio said. "We think that if an individual has two copies of this gene, he or she has a reasonable chance of having the disorder."

The researchers found that a person with two copies of the gene is five times more likely to have symptoms of SAD than a person without the mutation.

"That is a very high effect for a mental illness, because most mental illnesses have many potential causes," Provencio noted. "A mental illness may arise from many mutations, and we have found one that has a clear link."

The melanopsin gene encodes a light-sensitive protein that is found in a class of photoreceptors in the retina that are not involved with vision, but are linked to many non-visual responses, such as the control of circadian rhythms, the control of hormones, the mediation of alertness and the regulation of sleep.

The mutation in this gene may result in aberrant regulation of these responses to light, leading to the depressive symptoms of SAD. About 29 percent of SAD patients come from families with a history of the disorder, suggesting a genetic or hereditary link.

"The finding suggest that melanopsin mutations may predispose some people to SAD, and that if you have two copies of this mutation, there is a very high probability that you will be afflicted," Provencio said. "An eventual understanding of the mechanisms underlying the pathological response to light in SAD may lead to improved treatments."

Provencio added that the finding, with further study, could also lead to improved testing for SAD.
http://www.sciencedaily.com/releases/2008/11/081103130931.htm

 

Body Clock Regulates Metabolism

Mar. 19, 2009 —
Science Daily/University of California – Irvine
UC Irvine researchers have discovered that circadian rhythms – our own body clock – regulate energy levels in cells. The findings have far-reaching implications, from providing greater insights into the bond between the body's day-night patterns and metabolism to creating new ways to treat cancer, diabetes, obesity and a host of related diseases.

In addition, Paolo Sassone-Corsi, Distinguished Professor and Chair of Pharmacology, and his colleagues found that the proteins involved with circadian rhythms and metabolism are intrinsically linked and dependent upon each other. Their study appears online in Science Express on March 12.

"Our circadian rhythms and metabolism are closely partnered to ensure that cells function properly and remain healthy," Sassone-Corsi said. "This discovery opens a new window for us to understand how these two fundamental processes work together, and it can have a great impact on new treatments for diseases caused by cell energy deficiencies."

Circadian rhythms of 24 hours govern fundamental physiological functions in almost all organisms. The circadian clocks are the essential time-tracking systems in our bodies that anticipate environmental changes and adapt to the appropriate time of day. Disruption of these rhythms can profoundly influence human health and has been linked to obesity, diabetes, insomnia, depression, coronary heart diseases and cancer.

Sassone-Corsi already had identified that the enzyme protein CLOCK is an essential molecular gear of the circadian machinery and interacts with a protein, SIRT1, which senses cell energy levels and modulates aging and metabolism.

In this study, he and his colleagues show that CLOCK works in balance with SIRT1 to direct activity in a cell pathway by which metabolic proteins send signals called the NAD+ salvage pathway. In turn, a key protein in that pathway, NAMPT, helps control CLOCK levels, creating a tightly regulated codependency between our circadian clock and metabolism.

"When the balance between these two vital processes is upset, normal cellular function can be disrupted," Sassone-Corsi said. "And this can lead to illness and disease."

The findings suggest that proper sleep and diet may help maintain or rebuild this balance, he said, and also help explain why lack of rest or disruption of normal sleep patterns can increase hunger, leading to obesity-related illnesses and accelerated aging.

The specific interaction between CLOCK and SIRT1 and the NAD+ salvage pathway also presents a starting point for drug development aimed at curbing cell dysfunction and death, thereby helping to solve major medical problems such cancer and diabetes.
http://www.sciencedaily.com/releases/2009/03/090312140840.htm

Long, Short Sleep Durations Are Associated With Increased Risk For Diabetes

June 12, 2009 —
Science Daily/American Academy of Sleep Medicine
According to a research abstract that will be presented on June 8, at Sleep 2009, the 23rd Annual Meeting of the Associated Professional Sleep Societies, both long and short sleepers are at greater risk for diabetes. Individuals sleeping for more than eight hours per night may be particularly vulnerable.

Results indicate that the adjusted odds ratio was 1.24 for diabetes associated with short sleep (five hours per night or less) and 1.48 for diabetes associated with long sleep (nine or more hours per night). The prevalence of diabetes was 12 percent for blacks and 8 percent for whites, and the prevalence of obesity (body mass index of 30 kg/m2 or greater) was 52 percent for blacks and 38 percent for whites.

According to lead author Girardin Jean-Louis, PhD, associate professor at the SUNY Downstate Medical Center at the Brooklyn Health Disparities Research Center in New York, findings suggest that both patients who have excessive or insufficient sleep time have increased risk for developing diabetes, a serious health condition.

"Both blacks and whites who were obese tended to have short sleep time. These findings suggest that race significantly influenced the risk of obesity conferred by short sleep duration," said Jean-Louis. "As obesity is associated with diabetes and sleep apnea, it may be that more blacks are at risk for sleep apnea and diabetes, which are both linked to cardiovascular disease."

The study involved data from 29,818 individuals who completed the 2005 National Health Interview Survey, a cross-sectional household interview survey using multistage area probability and design. Data were collected from all 50 states and Washington, D.C. Participants were between the ages of 18 and 85 years; 85 percent of the sample was white and 15 percent was black; 56 percent of participants were women.
http://www.sciencedaily.com/releases/2009/06/090608071800.htm

 

Less Sleep Associated With High, Worsening Blood Pressure In Middle Age

June 11, 2009 —
Science Daily/JAMA and Archives Journals
Middle-aged adults who sleep fewer hours appear more likely to have high blood pressure and to experience adverse changes in blood pressure over time, according to a report in the June 8 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Almost one-third of Americans have hypertension or high blood pressure, a condition that contributes to 7 million deaths worldwide each year, according to background information in the article. "Identifying a novel lifestyle risk factor for high blood pressure could lead to new interventions to prevent or reduce high blood pressure," the authors write. "Laboratory studies of short-term sleep deprivation have suggested potential mechanisms for a causal link between sleep loss and hypertension." Sleep deprivation is associated with increased activity in the sympathetic nervous system, which controls the body's stress response. Over time, this activation could contribute to high blood pressure.

Kristen L. Knutson, Ph.D., of the University of Chicago, and colleagues studied 578 adults who first had their blood pressure and other clinical, demographic and health variables measured between 2000 and 2001. In 2003 and 2005, sleep duration was measured using surveys and wrist actigraphy, in which a sensor is worn on the wrist to record periods of rest and activity. Blood pressure, demographic and self-reported sleep information were measured again in 2005 and 2006.

Participants (average age 40.1) slept an average of six hours per night; only seven (1 percent) averaged eight or more hours of sleep. After excluding patients taking medication for high blood pressure and controlling for age, race and sex, the researchers found that individuals who slept fewer hours were significantly more likely to have higher systolic (top number) and diastolic (bottom number) blood pressure.

Sleeping less also predicted increases in blood pressure over five years, along with the onset of hypertension. Each hour of reduction in sleep duration was associated with a 37 percent increase in the odds of developing high blood pressure.

"Consistent with other studies, we observed higher blood pressure levels in men, particularly African American men," the authors write. "Also, as described in a previous report from this study, African American men slept much less than white women. These two observations suggested the intriguing possibility that the well-documented higher blood pressure in African Americans and men might be partly related to sleep duration."

"In summary, the present study provides evidence for a link between the duration and quality of sleep and high blood pressure levels using objectively measured sleep characteristics," they conclude. "Intervention studies are needed to determine whether optimizing sleep duration and quality can reduce the risk of increased blood pressure."
http://www.sciencedaily.com/releases/2009/06/090608162428.htm

 

Genes Regulating Circadian Rhythm Disturbed In Individuals With Arthritis

June 16, 2009 —
Science Daily/European League Against Rheumatism
The genes that regulate human circadian rhythm, or 'the body clock', are significantly disturbed in individuals with arthritis, according to the results of a new study presented today at EULAR 2009, the Annual Congress of the European League Against Rheumatism in Copenhagen, Denmark. Notably, a specific genetic pathway has been identified as responsible for interactions between the genes that regulate the body clock and those that may worsen symptoms of arthritis.

In a sample of 200 rheumatoid arthritis (RA) patients, sleep was determined to be significantly disturbed in over 61%, as determined by a Pittsburg Sleep Quality Index (PSQI) score of >5 (the PSQI global score was 8.55 ±4.69). These values were shown to correlate with several measures of arthritis disease activity, including levels of c-reactive protein, swollen joint count and DAS28*.

A further element of the study looked into the expression patterns of certain genes in mice with arthritis. Here, researchers identified a novel biochemical pathway in which the circadian regulatory gene CRY was found to up-regulate expression of a gene which promotes the activation of TNF-alpha (tumour necrosis factor-alpha, a pro-inflammatory cytokine used by the body to boost the immune system) by two fold, when comparing mice with the CRY gene removed to those with a normal copy of the gene.

Professor Shunichi Shiozawa of Kobe University Graduate School of Medicine and University Hospital, Japan, who led the research said: "Our study has shown that arthritis interferes with the genetics behind an individual's circadian rhythm and, specifically, that certain body clock genes may play a part in the activation of TNF-alpha, a signaling molecule that has an important role in the inflammation commonly seen in a number of rheumatologic conditions. The identification of this curious pathway may help to explain the 24-hour symptom cycle seen by many patients who experience worsening of joint pain and stiffness in the mornings, and lead to further research into new approaches for improving daily quality of life."

RA patients who participated in the study were attending the Kakogawa Konan Hospital and Kobe University Hospitals. Experimental arthritis was induced in mice with the CRY gene removed. Expression of the genes responsible for regulation of the human body clock were determined by immunohistochemistry and quantitative Polymerase Chain Reaction. TNF-alpha levels were measured by ELISA, and transactivation of TNF-alpha gene was examined by reporter assay.
http://www.sciencedaily.com/releases/2009/06/090610124629.htm

 

Under A Cloud: Darkness Linked To 'Brain Drain' In Depressed People

July 29, 2009 —
Science Daily/BioMed Central
A lack of sunlight is associated with reduced cognitive function among depressed people. Researchers writing in BioMed Central's open access journal Environmental Health used weather data from NASA satellites to measure sunlight exposure across the United States and linked this information to the prevalence of cognitive impairment in depressed people.

"We found that among participants with depression, low exposure to sunlight was associated with a significantly higher predicted probability of cognitive impairment. This relationship remained significant after adjustment for season. This new finding that weather may not only affect mood, but also cognition, has significant implications for the treatment of depression, particularly seasonal affective disorder."

Kent and his colleagues speculate that the physiological mechanisms that give rise to seasonal depression may also be involved in sunlight's effect on cognitive function in the context of depressive symptoms. Cognitive function was assessed by measurement of short-term recall and temporal orientation. As well as regulating the hormones serotonin and melatonin, light has been shown to also affect brain blood flow, which has in turn been linked with cognitive functions.

The researchers write: "Discovering the environment's impact on cognitive functioning within the context of seasonal disorders may lead not only to better understanding of the disorders, but also to the development of targeted interventions to enhance everyday functioning and quality of life."
http://www.sciencedaily.com/releases/2009/07/090727191728.htm

 

Tired Doctors Make More Mistakes

Sep. 27, 2009 —
Science Daily/Inderscience
A study of clinical errors made by resident physicians in a teaching hospital reveals that the more tired they are the more mistakes they make. The study published in the International Journal of Behavioural and Healthcare Research puts figures to this seemingly obvious conclusion and shows that fewer errors are made if clinical practices are standardised. The research could help promote the case for improved working conditions for junior doctors in order to improve patient outcomes.

Zvi Stern of the Hadassah Hebrew University Medical Center in Jerusalem, Israel, and colleagues report that resident physicians, colloquially known as "residents" are the frontline providers of the majority of in-patient medical care in teaching hospitals. The work is stressful, has often overwhelming responsibilities, and involves working long hours with little opportunity for adequate sleep and recuperation. Previous research has shown that sleep deprivation due to long working hours is a major factor in clinical errors made by residents.

The Harvard Work Hours, Health and Safety Study presented the most rigorous proof that fatigue causes medical errors and led to the US Accreditation Council for graduate medical education limiting residents' working hours. However, this has been criticised more recently in light of the fact that even with reduced hours errors made by residents remain a major problem in many teaching hospitals.
http://www.sciencedaily.com/releases/2009/09/090914111307.htm

Sounds Can Penetrate Deep Sleep and Enhance Associated Memories Upon Waking

Nov. 20, 2009 —
Science Daily/Northwestern University
They were in a deep sleep, yet sounds, such as a teakettle whistle and a cat's meow, somehow penetrated their slumber.

The 25 sounds presented during the nap were reminders of earlier spatial learning, though the Northwestern University research participants were unaware of the sounds as they slept.

Yet, upon waking, memory tests showed that spatial memories had changed. The participants were more accurate in dragging an object to the correct location on a computer screen for the 25 images whose corresponding sounds were presented during sleep (such as a muffled explosion for a photo of dynamite) than for another 25 matched objects.

"The research strongly suggests that we don't shut down our minds during deep sleep," said John Rudoy, lead author of the study and a neuroscience Ph.D. student at Northwestern. "Rather this is an important time for consolidating memories."

Most provocatively, the research showed that sounds can penetrate deep sleep and be used to guide rehearsal of specific information, pushing people's consolidation of memories in one direction over another.

"While asleep, people might process anything that happened during the day -- what they ate for breakfast, television shows they watched, anything," said Ken Paller, senior author of the study and professor of psychology in the Weinberg College of Arts and Sciences at Northwestern. "But we decided which memories our volunteers would activate, guiding them to rehearse some of the locations they had learned an hour earlier."

The Northwestern study adds a new twist to a growing body of research showing that memories are processed during sleep. It substantiates the literature showing that the brain is very busy during sleep, going over recently acquired information and integrating it with other knowledge in a mysterious consolidation process that sustains our memory abilities when awake.

"Strengthening Individual Memories by Reactivating Them During Sleep" will be published in the journal Science Nov. 20. Besides Paller and Rudoy, the paper's co-authors are Northwestern colleagues Joel L. Voss and Carmen E. Westerberg.

Whether or not memories are processed during sleep has been a subject of controversy, with most of the research on the topic focusing on REM, a normal stage of sleep characterized by rapid movement of the eyes. Vividly recalled dreams mostly occur during REM sleep. Recent research, including the new Northwestern study, however, focuses on memory processing during deep sleep, rather than during REM sleep.

"We are beginning to see that deep sleep actually is a key time for memory processing," Paller said.

Prior to their naps, the 12 study participants were taught to associate each of 50 images with a random location on a computer screen. Each object, such as a shattering wine glass, was paired with a corresponding sound, such as that of breaking glass, delivered over a speaker.

Locations were learned by repeating trials until study participants got quite good at placing all the objects in their assigned places. Approximately 45 minutes after learning, each participant reclined in a quiet, darkened room. Electrodes attached to their scalp measured their brain activity, indicating when they were asleep. Sleep sounds were presented without waking anyone up. When asked later, none of the participants thought sounds had been played during the naps. Yet, memory testing showed that placements of the objects were more accurate for those cued by their associated sounds during sleep than for those not cued.

"Our little experiment opens the door to many questions," Paller said.

Would high-school students do better on SAT tests if daytime studying was supplemented with sleep sounds at night? Would students learning foreign vocabulary words or other facts do better in the morning after listening to related information as they slept? Infants spend an inordinate amount of time sleeping, while their brains work over their recent experiences. Could an infant learn a first language more quickly if stimulation occurred during naps or overnight? What about an actor trying to learn lines or a law student trying to memorize numerous details of case law? Could playing sounds related to such learning improve the recall of relevant facts the next day?

The study opens avenues for discovering boundaries of what can happen to memories during sleep, said co-author Voss. "Can memories be distorted as well as strengthened? Can people be guided to forget unwanted memories?"

Much work remains to determine whether the results of the new research translate to these and other contexts, Paller emphasized. "We don't know the answers at this point," he said, "but more experiments about memory processing during sleep are certain to follow."
http://www.sciencedaily.com/releases/2009/11/091119193632.htm

 

Insomnia Prevalent Among Cancer Patients Who Receive Chemotherapy

Nov. 23, 2009 —
Science Daily/University of Rochester Medical Center
Three quarters of cancer patients and survivors treated with chemotherapy suffer insomnia or sleep disorders that often become chronic conditions, hindering patients' ability to fully recover, according to scientists at the University of Rochester Medical Center.

A study of 823 cancer patients showed they experienced sleep troubles at nearly three times the rate of the general population. The problem was more prevalent in younger patients and those with lung and breast cancers, according to the paper published online in the Journal of Clinical Oncology.

"These numbers are very high and something we can't ignore," said Oxana Palesh, Ph.D., M.P.H., research assistant professor of Radiation Oncology at the Medical Center's James P. Wilmot Cancer Center and lead author of the paper. "The good news is that insomnia is a very treatable problem that can be addressed quickly so it doesn't compound other symptoms."

Palesh reviewed data on patients who received chemotherapy between 1997 and 1999 at private practice medical oncology groups who were part of the National Cancer Institute's Community Clinical Oncology Program (CCOP.)

Patients answered questionnaires after their first two chemotherapy treatments. Responses to sleep-related questions showed that 37 percent of participants suffered from insomnia symptoms and another 43 percent had insomnia syndrome, as categorized by the Hamilton Depression Inventory, a widely used measure for symptoms of depression. These patients had difficulty falling asleep and staying asleep at least three days per week.

The challenge is that once people experience sleep problems and related fatigue, they begin taking naps and going to bed earlier, which perpetuates the problem and is counter-productive to getting restorative sleep at night, Palesh said.

Sleep problems are generally combined with patients complaints of fatigue and depression however, it has not been studied to determine the causes and impact on patients' quality of life.

Authors of the National Cancer Institute-funded study recognize many factors can cause sleep difficulties, such as depression and anxiety, but note the duration of treatment and extended sleep disruptions can contribute to other health problems.
http://www.sciencedaily.com/releases/2009/11/091123171240.htm

 

Chronic Drinking Can Disrupt Circadian Rhythms

Aug. 25, 2010 —
Science Daily/Alcoholism: Clinical & Experimental Research
Circadian rhythmicity is regulated by circadian clock genes, and animal studies have shown that chronic drinking can alter expressions in these genes. A new study has found that significantly lower levels of messenger ribonucleic acid (mRNA) -- a molecule of RNA that helps to manufacture proteins -- in circadian clock genes in alcohol-dependent (AD) patients support a relationship between circadian clock gene dysregulation and drinking in humans.

"The body's daily biological, or circadian, rhythms modulate our physiological functions and related behaviors such as body temperature, hormone secretions, and sleep/wake cycle," explained Sy-Jye Leu, a researcher with the Taipei Medical University and corresponding author for the study. "Circadian rhythms are the outward manifestation of an internal timing system which is driven by several genetic elements, what we call circadian clock genes." The appropriate expression or regulation of these genes is necessary for any organism to efficiently "program" physiological and behavioral activities in order to ensure survival, she said.

"AD is related to circadian rhythm dysfunction such as sleep problems and mood changes," added Chian-Jue Kuo, attending psychiatrist and assistant professor at Taipei City Hospital. "This study is important because the authors used a clinical sample, instead of animal models, to look into circadian dysregulation in AD patients."

"Previous studies had demonstrated that alcohol could directly disrupt … neuronal transmission in the brain," said Leu. "This would, in turn, influence the activity of circadian clock genes and disturb circadian rhythm-related responses. Assessing the levels of mRNA offers a direct measurement of gene expression of the circadian clock genes, and we can simultaneously assess nearly all of them."

Leu and her colleagues examined blood samples from 22 male patients who met the Diagnostic and Statistical Manual of Mental Disorders -- Fourth Edition criteria for AD, as well as 12 healthy "control" subjects for comparison.

Results showed markedly lower baseline mRNA levels of the target circadian clock genes in the AD patients than in the control subjects, which indicates an overall lowering of circadian clock gene expression in individuals with chronic drinking.

"In other words, chronic alcohol consumption was associated with a destruction of normal circadian clock gene expression," said Leu. "This altered expression is closely related to circadian rhythm dysfunction and might link to a variety of physiological problems such as sleep/wake cycle dysregulation, depression, and even cancer."

In addition, said Leu, the reduced gene expression did not restore following early alcohol withdrawal treatment. "This provides the first human evidence that chronic drinking can have long-term damaging effects on the expression of circadian rhythm-responsible genes," she said. "It also lends clinical support to previous reports of circadian rhythm dysregulation as a consequence of chronic drinking."
http://www.sciencedaily.com/releases/2010/08/100824161428.htm

Tick Tock: Rods Help Set Internal Clocks

Sep. 18, 2010 —
Science Daily/Johns Hopkins University
We run our modern lives largely by the clock, from the alarms that startle us out of our slumbers and herald each new workday to the watches and clocks that remind us when it's time for meals, after-school pick-up and the like.

The study results are important because they indicate that prolonged exposure to dim or low light at night (such as that in homes and office buildings) can influence mammals' biological clocks and "throw off" their sleep-wake cycles. Hattar suggested that one way people can mitigate this effect is to make sure to get some exposure to bright day light every day. (The exposure to brighter, natural daylight will firmly reset the clocks to a proper asleep-at-night-awake-in-the-day cycle.)

In addition, the study has possible implications for older people being cared for in nursing homes and hospitals, he said.

"Older adults often lose their rod cells to age, which means that their caretakers would be well advised to regularly and deliberately expose them to bright natural daylight in order to make sure that their natural, biological rhythms remain in sync so their sleep-wake cycles remain accurately set," Hattar said. "Otherwise, they could have sleep disturbances, such as intermittent waking or difficulty falling asleep, not to mention the impact on their appetite and other bodily functions."
http://www.sciencedaily.com/releases/2010/09/100917161154.htm

Need a nap? Find yourself a hammock

June 21, 2011
Science Daily/Cell Press
For grownups, drifting off for an afternoon snooze is often easier said than done. But many of us have probably experienced just how simple it can be to catch those zzz's in a gently rocking hammock. By examining brain waves in sleeping adults, researchers now have evidence to explain why that is.
http://images.sciencedaily.com/2011/06/110620122030-large.jpg

The study finds that napping on a slowly swinging bed really does get us to sleep faster. To the researchers' surprise, rocking also changes the nature of our sleep, encouraging deeper sleep.

"It is a common belief that rocking induces sleep: we irresistibly fall asleep in a rocking chair and, since immemorial times, we cradle our babies to sleep," said Sophie Schwartz of the University of Geneva. "Yet, how this works had remained a mystery. The goal of our study was twofold: to test whether rocking does indeed soothe sleep, and to understand how this might work at the brain level."

Schwartz, Michel Mühlethaler, and their colleagues Laurence Bayer and Irina Constantinescu asked twelve adult volunteers to nap on a custom-made bed or "experimental hammock" that could either remain stationary or rock gently. All participants were good sleepers who didn't typically nap and did not suffer from excessive sleepiness during the day. Each participant took two 45-minute afternoon naps, one with the bed stationary and one with the bed in motion, while their brain activity was monitored by electroencephalogram (EEG).

"We observed a faster transition to sleep in each and every subject in the swinging condition, a result that supports the intuitive notion of facilitation of sleep associated with this procedure," Mühlethaler said. "Surprisingly, we also observed a dramatic boosting of certain types of sleep-related [brain wave] oscillations."

More specifically, rocking increased the duration of stage N2 sleep, a form of non-rapid eye movement sleep that normally occupies about half of a good night's sleep. The rocking bed also had a lasting effect on brain activity, increasing slow oscillations and bursts of activity known as sleep spindles. Those effects are consistent with a more synchronized neural activity characteristic of deeper sleep.

Schwartz and Mühlethaler say the next step is to find out whether rocking can improve longer periods of sleep and to find out whether it may be useful for the treatment of sleep disorders, such as insomnia. Also, they added, because sleep spindles have been associated with brain plasticity mechanisms, enhancing spindle activity with rocking may be good for memory consolidation and may have the potential to improve brain repair mechanisms after brain damage.
http://www.sciencedaily.com/releases/2011/06/110620122030.htm

 

Electromagnetic fields can disturb learning but only at very high levels

July 1, 2011
Science Daily/Ruhr-Universitaet-Bochum
The effects of high-frequency electromagnetic fields emitted by mobile phones on humans have been hotly debated for years. In a new study, neuroscientists from Germany have shed light on this question. For the first time, they provide evidence that extremely high-powered electromagnetic fields can influence learning processes on the synaptic level within the brain, independent from other factors such as stress. However, such high levels are not encountered during typical use of mobile phones, the researchers note.

The results: Although there was daily training and effortless contact to the exposure environment, increases in blood derived stress hormone levels could be detected for all exposed groups. The stress clearly influences learning and memory formation on the synaptic level in the rat brain. High-powered EMFs (SAR 10 W/kg) also have a significant effect on learning and memory formation. In contrast to this, weak EMFs (SAR 0 and 2 W/kg) lead to no detectable changes or impairments.

"These results cannot directly be transferred to humans," says Nora Prochnow. "But in the animal model, it can be demonstrated that neuronal mechanisms of synaptic learning can serve as a target for high powered EMFs."

However, there is no need for serious concerns: humans are not exposed to such high-powered EMFs during daily mobile phone use. Nevertheless, the matter has to be regarded differently in special occupational situations, for instance during the use of body worn antenna systems as it is common for security services or military purposes. Here, critical levels for occupational exposure may be reached more easily and have to be controlled carefully.
http://www.sciencedaily.com/releases/2011/06/110630091657.htm

Behavioral treatment for migraines a cost-effective alternative to meds


July 5, 2011
Science Daily/University of Mississippi Medical Center
A cost analysis of migraine treatments comparing pharmaceuticals to well-documented behavioral approaches such as relaxation training, hypnosis and biofeedback found behavioral treatments often come out cheaper, particularly after a year or more.

The most expensive behavioral treatment method -- individual sessions with a psychologist in clinic -- cost more than pharmacologic treatment with $6-a-day drugs in the first months. But at about five months, individual sessions become competitive. After a year, they are cheaper than all methods except treatment with drugs costing 50 cents or less a day.
http://www.sciencedaily.com/releases/2011/07/110705123623.htm

 

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