High blood pressure treatment may slow cognitive decline

September 5, 2019

Science Daily/American Heart Association

Among middle-aged and older adults, high blood pressure accelerated cognitive decline and treatment slowed the regression. The rate of cognitive decline was similar between adults receiving high blood pressure treatment and those who did not have high blood pressure at all.

High blood pressure appears to accelerate cognitive decline among middle-aged and older adults and treating high blood pressure may slow down the process, according to a preliminary research presented at the American Heart Association's Hypertension 2019 Scientific Sessions.

The findings are important because high blood pressure and cognitive decline are two of the most common conditions associated with aging, and more people are living longer worldwide.

According to the American Heart Association's 2017 Hypertension Guidelines, high blood pressure is a global health threat, affecting approximately 80 million U.S. adults and one billion people globally. Moreover, the relationship between brain health and high blood pressure is a growing interest as researchers examine how elevated blood pressure affects the brain's blood vessels, which in turn, may impact memory, language and thinking skills.

In this observational study, researchers from Columbia University analyzed data collected on nearly 11,000 adults from the China Health and Retirement Longitudinal Study (CHARLS) between 2011-2015, to assess how high blood pressure and its treatment may influence cognitive decline. High blood pressure was defined as having a systolic blood pressure of 140 mmHg or higher and a diastolic blood pressure of 90 mmHg or higher, and/or taking antihypertensive medications. (Note: The American Heart Association guidelines define high blood pressure as 130 mmHg or higher or a diastolic reading of 80 mmHg or higher.)

Researchers in China interviewed study participants at home about their high blood pressure treatment, education level and noted if they lived in a rural or urban environment. They were also asked to perform cognitive tests, such as immediately recalling words as part of a memory quiz.

Among the study's findings:

Overall cognition scores declined over the four-year study;

Participants ages 55 and older who had high blood pressure showed a more rapid rate of cognitive decline compared with participants who were being treated for high blood pressure and those who did not have high blood pressure; and

The rate of cognitive decline was similar between those receiving high blood pressure treatment and those who did not have high blood pressure.

The study did not evaluate why or how high blood pressure treatments may have contributed to slower cognitive decline or if some treatments were more effective than others.

"We think efforts should be made to expand high blood pressure screenings, especially for at-risk populations, because so many people are not aware that they have high blood pressure that should be treated," said presenting study author Shumin Rui, a biostatistician at the Mailman School of Public Health, Columbia University in New York. "This study focused on middle-aged and older adults in China, however, we believe our results could apply to populations elsewhere as well. We need to better understand how high blood pressure treatments may protect against cognitive decline and look at how high blood pressure and cognitive decline are occurring together."

Fish intake associated with boost to antidepressant response

Science Daily/European College of Neuropsychopharmacology (ECNP)
October 20, 2014
Up to half of patients who suffer from major depression do not respond to treatment with Selective Serotonin Reuptake Inhibitors. Now a group of researchers has carried out a study that shows that increasing fatty fish intake appears to increase the response rate in patients who do not respond to antidepressants.

According to lead researcher, Roel Mocking (Amsterdam): "We were looking for biological alterations that could explain depression and antidepressant non-response, so we combined two apparently unrelated measures: metabolism of fatty acids and stress hormone regulation. Interestingly, we saw that depressed patients had an altered metabolism of fatty acids, and that this changed metabolism was regulated in a different way by stress hormones."

The researchers were looking at the relationship between depression and fatty acids, and various hormones, including the stress hormone cortisol. They took 70 patients with depression and compared them to 51 healthy controls, by measuring their fatty acid levels and cortisol levels. They then gave the depressed patients 20mg of an SSRI daily for 6 weeks, and in those who did not respond to the SSRIs the dose was gradually increased up to 50mg/day. Fatty acid and cortisol levels were measured during the trial.

They found that the MDD patients who didn't respond to the SSRI also tended to have abnormal fatty acid metabolism, so they checked the dietary habits of all those taking part in the trial. Fatty fish is rich in fatty acids, such as the well-known Omega-3 DHA. So the researchers looked at the amount of fatty fish in the diet of all involved in the trial. They categorised the patients into 4 groups, according to their fatty fish intake, and they found that those who took the least fish tended to respond badly to anti-depressants, whereas those who had most fish in the diet responded best to anti-depressants. Those who ate fatty fish at least once a week had a 75% chance of responding to antidepressants, whereas those who never ate fatty fish had only a 23% chance of responding to antidepressants.

Roel Mocking continued: "This means that the alterations in fatty acid metabolism (and their relationship with stress hormone regulation) were associated with future antidepressant response. Importantly, this association was associated with eating fatty fish, which is an important dietary source of omega-3 fatty acids. These findings suggest that measures of fatty acid metabolism, and their association with stress hormone regulation, might be of use in the clinic as an early indicator of future antidepressant response. Moreover, fatty acid metabolism could be influenced by eating fish, which may be a way to improve antidepressant response rates."

http://www.sciencedaily.com/releases/2014/10/141020090142.htm

Evidence for the existence of a hypnotic state? Key may be in the glazed staring eyes

October 25, 2011

Science Daily/Suomen Akatemia (Academy of Finland)

A multidisciplinary group of researchers from Finland and Sweden has found that the strange stare of patients under hypnosis may be a key that can eventually lead to a solution to a long debate about the existence of a hypnotic state

One of the most widely known features of a hypnotized person in the popular culture is a glazed, wide-open look in the eyes. Paradoxically, this sign has not been considered to have any major importance among researchers and has never been studied in any detail, probably due to the fact that it can be seen in only some hypnotized people.

Published in the online journal PLoS ONE, the study was done with a very highly hypnotizable participant who can be hypnotized and dehypnotized by just using a one-word cue. The change between hypnotic state and normal state can thus be varied in seconds.

The researchers used high-resolution eye-tracking methodology and presented a set of well-established oculomotor tasks that trigger automatic eye behavior. They found the glazed stare was accompanied by objectively measurable changes in automatic, reflexive eye behavior that could not be imitated by non-hypnotized participants.

In the field of hypnosis research this result means that hypnosis can no longer be regarded as mental imagery that takes place during a totally normal waking state of consciousness. On the other hand, the result may have wider consequences for psychology and cognitive neuroscience, since it provides the first evidence of the existence of a conscious state in humans that has previously not been scientifically confirmed.

Hypnosis has had a long and controversial history in psychology, psychiatry and neurology. For over 100 years researchers have debated if a special hypnotic state exists or whether it is just about using cognitive strategies and mental imagery in a normal waking state. So far, a hypnotic state has never been convincingly demonstrated, and therefore, many researchers regard the hypnotic state to be just a popular myth in psychology.

http://www.sciencedaily.com/releases/2011/10/111025091559.htm

High to moderate levels of stress lead to higher mortality rate

October 21, 2011

Science Daily/Oregon State University

A new study concludes that men who experience persistently moderate or high levels of stressful life events over a number of years have a 50 percent higher mortality rate. In general, the researchers found only a few protective factors against these higher levels of stress -- people who self-reported that they had good health tended to live longer and married men also fared better. Moderate drinkers also lived longer than non-drinkers.

In general, the researchers found only a few protective factors against these higher levels of stress -- people who self-reported that they had good health tended to live longer and married men also fared better. Moderate drinkers also lived longer than non-drinkers.

"Being a teetotaler and a smoker were risk factors for mortality," said Carolyn Aldwin, lead author of the study and a professor of human development and family sciences at Oregon State University. "So perhaps trying to keep your major stress events to a minimum, being married and having a glass of wine every night is the secret to a long life."

This is the first study to show a direct link between stress trajectories and mortality in an aging population. Unlike previous studies that were conducted in a relatively short term with smaller sample sizes, this study was modified to document major stressors -- such as death of a spouse or a putting a parent into a retirement home -- that specifically affect middle-aged and older people.

Those in the low-stress group experienced an average of two or fewer major life events in a year, compared with an average of three for the moderate group and up to six for the high stress group. One of the study's most surprising findings was that the mortality risk was similar for the moderate versus high stress group.

"It seems there is a threshold and perhaps with anything more than two major life events a year and people just max out," Aldwin said. "We were surprised the effect was not linear and that the moderate group had a similar risk of death to the high-risk group."

http://www.sciencedaily.com/releases/2011/10/111020122441.htm

Brain study reveals stress code

October 9, 2011

Science Daily/University of Leicester

Neuroscientists investigating the 'brain code' claim to have made a significant step forwards in understanding how the brain deals with stress- and mitigates its impact.

Examining what they term 'thin' and 'mushroom-like' parts of nerve cells in the brain, which are responsible for learning and remembering, they discovered that it is possible to alter what is remembered -- thereby mitigating the stress of painful memories.

A team from the University of Leicester has identified a particular protein that the brain produces in response to stress. Tests on mice revealed that those without this protein were less 'outgoing' and preferred to 'hide in the dark'.

"We have identified a protein that the brain produces in response to stress in order to reduce the number of mushroom spines and therefore reduce future anxiety associated with stressful events. This protein, lipocalin-2, is normally not produced, but its fabrication dramatically increases in response to stress in the hippocampus. When we added lipocalin-2 to neurons in culture the way it occurs on stress, neurons started losing their "memory spines" -- the mature, mushroom-shaped ones.

"Thus, the brain produces lipocalin-2 in order to protect us from "too much anxiety" and help us cope with various adverse life events. "Identification of lipocalin-2 as a new player the brain uses to help us cope with stress is an important step forward. We are getting closer to deciphering molecular mechanisms of stress that, if not functioning properly, may lead to stress-related psychiatric diseases."

"Stress-related psychological and mental disturbances are extremely common and affect more than 30% of the population. We are keen to investigate whether the mechanisms discovered by us apply to humans and could help inform clinical strategies to deal with anxiety disorders and depression."

http://www.sciencedaily.com/releases/2011/10/111003151826.htm

Sleep disorders affect 40 percent of Canadians

September 8, 2011

Science Daily/Université Laval

Sleep disorders affect 40% of adult Canadians according to a study conducted by Université Laval researchers under the supervision of Dr. Charles M. Morin. The work of Dr. Morin and his colleagues will be presented at the 4th World Congress on Sleep Medicine which runs September 10-14 in Quebec City, Canada.

Although many respondents experienced at least one symptom of insomnia, only 13% said they had consulted a healthcare professional about it. The survey data revealed that Canadians use prescription medicine (10%), natural products (9%), over-the-counter drugs (7%), or alcohol (5%) to treat their sleep problems.

Surprisingly, the researchers observed that 9.5% of French speakers suffered from insomnia compared to 14.3% of English speakers. However, French speakers take more prescribed sedatives (13% vs. 9%) and natural products (16% vs. 7%) than English-speaking Canadians.

"Many people who suffer from insomnia try to treat the problem themselves rather than consulting a healthcare professional," said Dr. Morin, a professor and researcher at Université Laval's School of Psychology. "This is not a good idea because we don't know the risks and benefits of products that have not been approved by government health agencies," he explained.

Brain waves control the impact of noise on sleep

September 6, 2011

Science Daily/University of Liège

During sleep, our perception of the environment decreases. However the extent to which the human brain responds to surrounding noises during sleep remains unclear. Researchers have now used brain imaging to study responses to sounds during sleep. They show that brain activity in the face of noise is controlled by specific brain waves during sleep. Researchers found that perception of the environment is not continuously reduced during sleep, but rather varies throughout sleep under the influence of particular brain waves.

They show that brain activity in the face of noise is controlled by specific brain waves during sleep. In particular, waves called sleep 'spindles' prevent the transmission of sounds to auditory brain regions. Conversely, when sounds are associated with brain waves called 'K-complexes', activation of auditory areas is larger. Our perception of the environment is therefore not continuously reduced during sleep, but rather varies throughout sleep under the influence of particular brain waves.

Conversely, sounds can induce the production during sleep of brain waves called 'K-complexes'. The results brought by this new study demonstrate that production of K-complexes by sounds is associated with a larger activation of auditory brain areas. While spindles prevent the transmission of sounds, K-complexes reflect a more important transmission of sounds to the sleeping brain.

The effects of noise on sleep are therefore controlled by specific brain waves. In particular, the human brain is isolated from the environment during sleep spindles, which might allow essential sleep functions to operate such as the consolidation of memory for previously acquired information. These brain waves thus play a crucial role in sleep quality and stability in the face of noise.

http://www.sciencedaily.com/releases/2011/09/110906121014.htm

Increased light may moderate fearful reactions

August 12, 2011

Science Daily/University of Virginia

Biologists and psychologists know that light affects mood, but a new study indicates that light may also play a role in modulating fear and anxiety.

"We looked at the effect of light on learned fear, because light is a pervasive feature of the environment that has profound effects on behavior and physiology," said Wiltgen, an assistant professor of psychology and an expert on learning. "Light plays an important role in modulating heart rate, circadian rhythms, sleep/wake cycles, digestion, hormones, mood and other processes of the body. In our study we wanted to see how it affects learned fear."

"The implications of this in humans is this: that being diurnal, the absence of light can be a source of fear," Wiltgen said. "But increased light can be used to reduce fear and anxiety and to treat depression. If we can come to understand the cellular mechanisms that affect this, then eventually abnormal anxiety and fear might be treated with improved pharmaceuticals to mimic or augment light therapy."

http://www.sciencedaily.com/releases/2011/08/110810153707.htm

Music reduces anxiety in cancer patients

August 10, 2011

Science Daily/Wiley-Blackwell

Cancer patients may benefit from sessions with trained music therapists or from listening to music. A new systematic review shows using music can reduce anxiety in cancer patients, and may also have positive effects on mood, pain and quality of life.

"The evidence suggests that music interventions may be useful as a complementary treatment to people with cancer," said lead researcher Joke Bradt of the Department of Creative Arts Therapies at Drexel University in Philadelphia, US. "Music interventions provided by trained music therapists as well as listening to pre-recorded music both have shown positive outcomes in this review, but at this time there is not enough evidence to determine if one intervention is more effective than the other."

http://www.sciencedaily.com/releases/2011/08/110809212424.htm

New evidence of age-related decline in the brain's master circadian clock

July 25, 2011

Science Daily/University of California - Los Angeles

A new study of the brain's master circadian clock reveals that a key pattern of rhythmic neural activity begins to decline by middle age. The study may have implications for the enormous number of older people who have difficulty sleeping and adjusting to time changes.

"Aging has a profound effect on circadian timing," said Block, a professor of psychiatry and biobehavioral sciences and of physiological science. "It is very clear that animals' circadian systems begin to deteriorate as they age, and humans have enormous problems with the quality of their sleep as they age, difficulty adjusting to time-zone changes and difficulty performing shift-work, as well as less alertness when awake. There is a real change in the sleep-wake cycle.

"The question is, what changes in the nervous system underlie all of that? This paper suggests a primary cause of at least some of these changes is a reduction in the amplitude of the rhythmic signals from the SCN." The SCN, located in the hypothalamus, is the central circadian clock in humans and other mammals and controls not only the timing of the sleep-wake cycle but also many other rhythmic and non-rhythmic processes in the body.

"With many neurological disorders, patients have a hard time sleeping during the night and staying awake during the day," said Colwell, who was a postdoctoral fellow in Block's lab in the early 1990s at the University of Virginia. "One of the main clinical complaints of patients with Huntington's disease and Parkinson's disease is they cannot sleep and do not respond well to sleeping pills. We think the same dysfunction we see with normal aging occurs much earlier and more severely with these patients, and we hope that the treatment strategies we develop for aging can be applied to help patients with neurodegenerative diseases as well. If we learn what is going wrong, then we may be able to develop treatments."

http://www.sciencedaily.com/releases/2011/07/110719093808.htm

Stress and alcohol 'feed' each other

July 19, 2011

Science Daily/Alcoholism: Clinical & Experimental Research

Acute stress is thought to precipitate alcohol drinking. Yet the ways that acute stress can increase alcohol consumption are unclear. A new study investigated whether different phases of response to an acute stressor can alter the subjective effects of alcohol. Findings indicate bi-directional relationships between alcohol and stress.

"Anecdotal reports suggest that alcohol dampens the physiological or negative emotional effects of stress but this has been hard to demonstrate in the lab," said Emma Childs, research associate at The University of Chicago and corresponding author for the study. "Another way that stress could increase drinking is by altering alcohol's effects. For example, if stress reduces the intoxicating effects of alcohol, individuals may drink more alcohol to produce the same effect.

Childs explained that the body's reaction to stress involves separate physiological and emotional consequences that occur at different times after the stress. "For example," she said, "the increase in heart rate and blood pressure, the release of cortisol, and also the increased feelings of tension and negative mood each reach a climax and dissipate at a different rate. Therefore, drinking more alcohol might have different effects, depending on how long after the stress a person drinks."

"The results demonstrated bi-directional relationships between alcohol and stress," said Childs. "Alcohol can change the way that the body deals with stress: it can decrease the hormone cortisol which the body releases to respond to stress, and it can prolong the feelings of tension produced by the stress. Stress can also change how alcohol makes a person feel: it can reduce the pleasant effects of alcohol or increase craving for more alcohol."

Childs added that it is often hard to separate alcohol's effects upon stress reactions from its effects on the perception of how stressful an experience is. "However, in our study we administered alcohol after the stressful experience, then examined the effects of alcohol on stress responses so ruling out any effect of alcohol upon perception of the stress. We showed that alcohol decreases the hormonal response to the stress, but also extends the negative subjective experience of the event. We also showed that stress decreased the pleasant effects of the alcohol. These findings illustrate a complex bi-directional interactions between stress and alcohol."

In summary, said Childs, using alcohol to cope with stress may actually make a person's response to stress worse, and prolong recovery from a stressor. "Stress may also alter the way that alcohol makes us feel in a way that increases the likelihood of drinking more alcohol," she said. "Stress responses are beneficial in that they help us to react to adverse events. By altering the way that our bodies deal with stress, we may be increasing the risks of developing stress-related diseases, not the least of which is alcohol addiction."

http://www.sciencedaily.com/releases/2011/07/110715163216.htm

New understandings of circadian rhythms

July 13, 2011

Science Daily/NIH/National Institute of General Medical Sciences

A tiny plant called Arabidopsis thaliana just helped scientists unearth new clues about the daily cycles of many organisms, including humans. This is the latest in a long line of research, much of it supported by the National Institutes of Health, that uses plants to solve puzzles in human health.

While other model organisms may seem to have more in common with us, greens like Arabidopsis provide an important view into genetics, cell division and especially light sensing, which drives 24-hour behavioral cycles called circadian rhythms.

Some human cells, including cancer cells, divide with a 24-hour rhythm. One of the main human circadian rhythm genes, cryptochrome, has been associated with diabetes and depression. Both of these discoveries grew from work with plants.

Scientists aren't yet certain why night is the best time for stems to grow, but Kay speculates it has to do with using resources efficiently. Plants pick up carbon and nitrogen during the day, then store these essential nutrients as starch and proteins. "In the later night, they can release these resources in a coordinated fashion to provide the building blocks for stem growth," says Kay. "Our understanding of human health and the role of clocks in health and disease can greatly benefit from studying how clocks work in plants," he adds.

How plants like Arabidopsis suppress harmful genes may also help improve HIV therapies. A team of biologists led by Craig Pikaard at Washington University in St. Louis is investigating RNA polymerases, chemicals important in determining which genes get switched on, to learn how plants silence harmful virus-derived genes. Similar silencing pathways could be harnessed for HIV therapies.

http://www.sciencedaily.com/releases/2011/07/110713131642.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

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

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.

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

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

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

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

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

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