Brutal Cold, Short Days, Post-Holiday Letdown Raise Risk of Depression
Jan. 3, 2014 —
Science Daily/Loyola University Health System
The first Monday after the holidays can be a depressing time for people coping with a post-holiday letdown and a type of depression triggered by short days called seasonal affective disorder (SAD).
For people affected by seasonal affective disorder, energy and mood take a nosedive during the short days of winter. "SAD is characterized by depression, exhaustion and lack of interest in people and regular activities," Halaris said. "It interferes with a person's outlook on life and ability to function properly."
Environmental stresses, such as brutally cold weather, can help trigger depression in people who already are vulnerable due to SAD, post-holiday blues or other factors, Halaris said.
SAD is thought to be related to a chemical imbalance in the brain, brought on by lack of light due to winter's shorter days and typically overcast skies. "With less exposure to light in the winter months, many people become depressed," Halaris said. "Those susceptible to SAD are affected even more so."
Halaris said that bright light affects brain chemistry in a helpful way and acts as an antidepressant. If you can stand the cold, get outside during the day, even if it is overcast. At home, open the drapes and blinds to let in natural light.
SAD can be effectively treated with light therapy, antidepressant medication and/or psychotherapy, Halaris said. The latest treatment is a headband containing mounted lights that delivers light to your retina whether you are inside or outdoors.
http://www.sciencedaily.com/releases/2014/01/140103205234.htm
Want a Good Night's Sleep in the New Year? Quit Smoking
January 2, 2014
Science Daily/Federation of American Societies for Experimental Biology
As if cancer, heart disease and other diseases were not enough motivation to make quitting smoking your New Year's resolution, here's another wake-up call: New research published in the January 2014 issue of The FASEB Journal suggests that smoking disrupts the circadian clock function in both the lungs and the brain. Translation: Smoking ruins productive sleep, leading to cognitive dysfunction, mood disorders, depression and anxiety.
"This study has found a common pathway whereby cigarette smoke impacts both pulmonary and neurophysiological function. Further, the results suggest the possible therapeutic value of targeting this pathway with compounds that could improve both lung and brain functions in smokers," said Irfan Rahman, Ph.D., a researcher involved in the work from the Department of Environmental Medicine at the University of Rochester Medical Center in Rochester, N.Y. "We envisage that our findings will be the basis for future developments in the treatment of those patients who are suffering with tobacco smoke-mediated injuries and diseases.
Rahman and colleagues found that tobacco smoke affects gene expression rhythms in the lung by producing parallel inflammation and depressed levels of brain locomotor activity.
http://www.sciencedaily.com/releases/2014/01/140102113120.htm
Daily rhythms of our genes are disrupted when sleep times shift
January 20, 2014
Science Daily/University of Surrey
A new study found that the daily rhythms of our genes are disrupted when sleep times shift.
http://images.sciencedaily.com/2014/01/140120173334-large.jpg
Researchers placed twenty-two participants on a 28-hour day in a controlled environment without a natural light-dark cycle. As a result, their sleep-wake cycle was delayed by four hours each day, until sleep occurred 12 hours out of sync with their brain clock and in the middle of what would have been their normal 'daytime'. The team then collected blood samples to measure the participants' rhythms of gene expression.
During this disruption of sleep timing, there was a six-fold reduction in the number of genes that displayed a circadian rhythm (a rhythm with an approximately 24 hour period). This included many regulators associated with transcription and translation, indicating widespread disruption to many biological processes.
The study also revealed which genes may be regulated by sleep-wake cycles and which are regulated by central body clocks. This finding provides new clues about sleep's function as separate from the circadian clock.
Senior author Professor Derk-Jan Dijk, from the Sleep Research Centre at the University of Surrey said: "This research may help us to understand the negative health outcomes associated with shift work, jet lag and other conditions in which the rhythms of our genes are disrupted.
"The results also imply that sleep-wake schedules can be used to influence rhythmicity in many biological processes, which may be very relevant for conditions in which our body clocks are altered, such as in ageing."
http://www.sciencedaily.com/releases/2014/01/140120173334.htm
Males and females differ in specific brain structures
February 11, 2014
Science Daily/University of Cambridge
Reviewing over 20 years of neuroscience research into sex differences in brain structure, researchers have conducted the first meta-analysis of the evidence. The team performed a quantitative review of the brain imaging literature testing overall sex differences in total and regional brain volumes. They found that males on average have larger total brain volumes than women (by 8 to 13 percent). Looking more closely, the researchers found differences in volume between the sexes were located in several regions. These included parts of the limbic system, and the language system.
The results highlight an asymmetric effect of sex on the developing brain. Amber Ruigrok, who carried out the study as part of her PhD, said: "For the first time we can look across the vast literature and confirm that brain size and structure are different in males and females. We should no longer ignore sex in neuroscience research, especially when investigating psychiatric conditions that are more prevalent in either males or females."
http://www.sciencedaily.com/releases/2014/02/140211094201.htm
How chronic stress predisposes brain to mental disorders
February 11, 2014
Science Daily/University of California - Berkeley
Biologists have shown in rats that chronic stress makes stem cells in the brain produce more myelin-producing cells and fewer neurons, possibly affecting the speed of connections between cells as well as memory and learning. This could explain why stress leads to mental illness, such as PTSD, anxiety and mood disorders, later in life.
Doctors know that people with stress-related illnesses, such as post-traumatic stress disorder (PTSD), have abnormalities in the brain, including differences in the amount of gray matter versus white matter. Gray matter consists mostly of cells -- neurons, which store and process information, and support cells called glia -- while white matter is composed of axons, which create a network of fibers that interconnect neurons. White matter gets its name from the white, fatty myelin sheath that surrounds the axons and speeds the flow of electrical signals from cell to cell.
How chronic stress creates these long-lasting changes in brain structure is a mystery that researchers are only now beginning to unravel.
In a series of experiments, Daniela Kaufer, UC Berkeley associate professor of integrative biology, and her colleagues, including graduate students Sundari Chetty and Aaron Freidman, discovered that chronic stress generates more myelin-producing cells and fewer neurons than normal. This results in an excess of myelin -- and thus, white matter -- in some areas of the brain, which disrupts the delicate balance and timing of communication within the brain.
"We studied only one part of the brain, the hippocampus, but our findings could provide insight into how white matter is changing in conditions such as schizophrenia, autism, depression, suicide, ADHD and PTSD," she said.
The hippocampus regulates memory and emotions, and plays a role in various emotional disorders.
Kaufer and her colleagues published their findings in the Feb. 11 issue of the journal Molecular Psychiatry.
Does stress affect brain connectivity?
Kaufer's findings suggest a mechanism that may explain some changes in brain connectivity in people with PTSD, for example. One can imagine, she said, that PTSD patients could develop a stronger connectivity between the hippocampus and the amygdala -- the seat of the brain's fight or flight response -- and lower than normal connectivity between the hippocampus and prefrontal cortex, which moderates our responses.
"You can imagine that if your amygdala and hippocampus are better connected, that could mean that your fear responses are much quicker, which is something you see in stress survivors," she said. "On the other hand, if your connections are not so good to the prefrontal cortex, your ability to shut down responses is impaired. So, when you are in a stressful situation, the inhibitory pathways from the prefrontal cortex telling you not to get stressed don't work as well as the amygdala shouting to the hippocampus, 'This is terrible!' You have a much bigger response than you should."
http://www.sciencedaily.com/releases/2014/02/140211153559.htm
Blue light may fight fatigue around the clock
February 3, 2014
Science Daily/Brigham and Women's Hospital
Researchers have found that exposure to short wavelength, or blue light, during the biological day directly and immediately improves alertness and performance.
"Our previous research has shown that blue light is able to improve alertness during the night, but our new data demonstrates that these effects also extend to daytime light exposure," said Shadab Rahman, PhD, a researcher in BWH's Division of Sleep Medicine and lead author of this study. "These findings demonstrate that prolonged blue light exposure during the day has an alerting effect."
The researchers found that participants exposed to blue light consistently rated themselves as less sleepy, had quicker reaction times and fewer lapses of attention during the performance tests compared to those who were exposed to green light. They also showed changes in brain activity patterns that indicated a more alert state.
"These results contribute to our understanding of how light impacts the brain and open up a new range of possibilities for using light to improve human alertness, productivity and safety," explained Steven Lockley, PhD, neuroscientist at BWH and senior investigator of the study. "While helping to improve alertness in night workers has obvious safety benefits, day shift workers may also benefit from better quality lighting that would not only help them see better but also make them more alert."
http://www.sciencedaily.com/releases/2014/02/140203191841.htm
Here comes the sun to lower your blood pressure
January 17, 2014
Science Daily/University of Southampton
Exposing skin to sunlight may help to reduce blood pressure and thus cut the risk of heart attack and stroke, a study published suggests. Research shows that sunlight alters levels of the small messenger molecule, nitric oxide (NO) in the skin and blood, reducing blood pressure.
The results suggest that UVA exposure dilates blood vessels, significantly lowers blood pressure, and alters NO metabolite levels in the circulation, without changing vitamin D levels. Further experiments indicate that pre-formed stores of NO in the upper skin layers are involved in mediating these effects. The data are consistent with the seasonal variation of blood pressure and cardiovascular risk at temperate latitudes.
Professor Feelisch adds: "These results are significant to the ongoing debate about potential health benefits of sunlight and the role of Vitamin D in this process. It may be an opportune time to reassess the risks and benefits of sunlight for human health and to take a fresh look at current public health advice. Avoiding excess sunlight exposure is critical to prevent skin cancer, but not being exposed to it at all, out of fear or as a result of a certain lifestyle, could increase the risk of cardiovascular disease. Perhaps with the exception of bone health, the effects of oral vitamin D supplementation have been disappointing.
http://www.sciencedaily.com/releases/2014/01/140117090139.htm
Call to scientists: Stop excluding left-handed people from scientific studies
February 13, 2014
Science Daily/Radboud University Nijmegen
Left-handed people really do have different brains and genes from right-handed people. Yet left-handed people are almost never included as study subjects in scientific research. Therefore in a new article, a call is launched for more research into left-handed people.
Left-handed people are rarely included as study subjects for brain or genetic research because the differences with right-handed people cause noise in the final results. However, left-handed people form about ten percent of the entire population and their brains and genes contain interesting information about the functioning of both halves of the brain as well as about several psychiatric disorders. 'Research into left-handed people is therefore interesting because of the noise they cause', thinks neuroscientist Roel Willems from the Donders Institute for Brain, Cognition and Behaviour at Radboud University Nijmegen. With the opinion article he calls upon his fellow researchers to stop excluding left-handed people from studies.
Missed chance for the neurosciences 'One of our studies from 2009 clearly shows why research into left-handed people is so vital', says Willems. 'According to the textbooks, facial recognition takes place in the right half of the brain. Our research revealed that the same process takes place in both halves of the brain in the case of left-handed people, but with the same final outcome. That is a fundamental difference. And left-handed people might process other important information differently as well. The minimal amount of research into this is, in my view, a missed chance for the neurosciences.
http://www.sciencedaily.com/releases/2014/02/140213112640.htm
Does more stress equal more headaches?
February 19, 2014
Science Daily/American Academy of Neurology (AAN)
A new study provides evidence for what many people who experience headache have long suspected—having more stress in your life leads to more headaches.
"These results show that this is a problem for everyone who suffers from headaches and emphasize the importance of stress management approaches for people with migraine and those who treat them," said study author Sara H. Schramm, MD, of University Hospital of University Duisburg-Essen in Germany. "The results add weight to the concept that stress can be a factor contributing to the onset of headache disorders, that it accelerates the progression to chronic headache, exacerbates headache episodes, and that the headache experience itself can serve as a stressor."
http://www.sciencedaily.com/releases/2014/02/140219162732.htm