Extended sleep reduces pain sensitivity

A new study suggests that extending nightly sleep in mildly sleepy, healthy adults increases daytime alertness and reduces pain sensitivity.

"Our results suggest the importance of adequate sleep in various chronic pain conditions or in preparation for elective surgical procedures," said Timothy Roehrs, PhD, the study’s principal investigator and lead author. "We were surprised by the magnitude of the reduction in pain sensitivity, when compared to the reduction produced by taking codeine."

The study, appearing in the December issue of the journal SLEEP, involved 18 healthy, pain-free, sleepy volunteers. They were randomly assigned to four nights of either maintaining their habitual sleep time or extending their sleep time by spending 10 hours in bed per night. Objective daytime sleepiness was measured using the multiple sleep latency test (MSLT), and pain sensitivity was assessed using a radiant heat stimulus.

Results show that the extended sleep group slept 1.8 hours more per night than the habitual sleep group. This nightly increase in sleep time during the four experimental nights was correlated with increased daytime alertness, which was associated with less pain sensitivity.

In the extended sleep group, the length of time before participants removed their finger from a radiant heat source increased by 25 percent, reflecting a reduction in pain sensitivity. The authors report that the magnitude of this increase in finger withdrawal latency is greater than the effect found in a previous study of 60 mg of codeine.

According to the authors, this is the first study to show that extended sleep in mildly, chronically sleep deprived volunteers reduces their pain sensitivity. The results, combined with data from previous research, suggest that increased pain sensitivity in sleepy individuals is the result of their underlying sleepiness.

Scientists create road map to metabolic reprogramming for aging

In efforts to understand what influences life span, cancer and aging, scientists are building road maps to navigate and learn about cells at the molecular level.

To survey previously uncharted territory, a team of researchers at UW-Madison has created an “atlas” that maps more than 1,500 unique landmarks within mitochondria that could provide clues to the metabolic connections between caloric restriction and aging.

The map, as well as the techniques used to create it, could lead to a better understanding of how cell metabolism is rewired in some cancers, age-related diseases and metabolic conditions such as diabetes.

"It’s really a dynamic atlas for regulatory points in mitochondrial function — there are many interesting avenues that other scientists can follow up on," says John Denu, University of Wisconsin-Madison professor of biomolecular chemistry and leader of the epigenetics theme at the Wisconsin Institute for Discovery (WID). "It could take years for researchers to understand what it all means, but at least now we have a list of the most important players."

(Image Credit: © Alexander Raths - Fotolia.com)

New Treatment Aids Weight Loss, Improves Diabetes in Monkeys

A new, lab-created antibody that mimics the action of a naturally occurring molecule causes weight loss in monkeys, researchers report.

The engineered antibody also appears to improve insulin sensitivity, which could fight type 2 diabetes, and it decreases levels of triglycerides, a blood fat that contributes to hardening of the arteries.

"The results we describe in animal models are profound and very encouraging," said study senior author Yang Li, scientific director at Amgen, Inc., in Thousand Oaks, Calif. "While we’re excited about these findings, we’re still evaluating the results."

Li said it’s important to remember these findings were in monkeys and only in a preclinical setting. It’s not yet clear how this treatment might act in humans.

The study was funded by Amgen, the developer of the new treatment. The findings are published in the Nov. 28 issue of Science Translational Medicine.

(Image: Courtesy of iStockphoto/GlobalP)

Is “Deep Learning” a Revolution in Artificial Intelligence?

Can a new technique known as deep learning revolutionize artificial intelligence as the New York Times suggests?

The technology on which the Times focusses, deep learning, has its roots in a tradition of “neural networks” that goes back to the late nineteen-fifties. At that time, Frank Rosenblatt attempted to build a kind of mechanical brain called the Perceptron, which was billed as “a machine which senses, recognizes, remembers, and responds like the human mind.” The system was capable of categorizing (within certain limits) some basic shapes like triangles and squares. Crowds were amazed by its potential, and even The New Yorker was taken in, suggesting that this “remarkable machine…[was] capable of what amounts to thought.”

But the buzz eventually fizzled; a critical book written in 1969 by Marvin Minsky and his collaborator Seymour Papert showed that Rosenblatt’s original system was painfully limited, literally blind to some simple logical functions like “exclusive-or” (As in, you can have the cake or the pie, but not both). What had become known as the field of “neural networks” all but disappeared.

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Research shows brain hub activity different in coma patients

A team of French and British researchers has found that brain region activity for coma patients is markedly different than for healthy people. In their paper published in the Proceedings of the National Academy of Sciences, the group describes the differences found when comparing fMRI scans of people in a coma with healthy volunteers.

To gain a better understanding of what goes on in the brain when a person is in a coma, and perhaps the nature of consciousness, the researchers performed fMRI brain scans on 17 people who had recently become comatose due to medical conditions that led to blockage of oxygen to the brain. They then compared those scans to those taken of 20 healthy volunteers.

In analyzing the results the team found that global comparisons between the two groups revealed very few if any differences. Blood continued to flow to all of the parts of the brain. When focusing on the brain as a network however, they found very large differences.

To look at the brain as a network requires looking at its different parts as regions that communicate with one another, forming hubs. In healthy people, certain regions or hubs are busier than others as evidenced by more blood flow. But for the people in a coma, the team found, the normally busy hubs grew less busy, while other hubs grew busier, indicating a major change in the flow of information.

The researchers suggest that the brain scans reveal that the normally busy hubs in healthy people are centers of consciousness and their reduced role in communications in comatose patients suggests that they are most likely not conscious of their existence. They point to prior research that has suggested that being in a coma is more likely closer to the experience of being under anesthesia than being asleep. They add that the their research indicates that regions of the brain that are responsible for conscience thought likely require more oxygen rich blood, and are thus likely to be more sensitive to oxygen deprivation than other areas of the brain, which might explain why people go into a coma when those regions are harmed.

Vitamin D Tied to Women’s Cognitive Performance

Two new studies appearing in the Journals of Gerontology Series A: Biological Sciences and Medical Sciences show that vitamin D may be a vital component for the cognitive health of women as they age.

Higher vitamin D dietary intake is associated with a lower risk of developing Alzheimer’s disease, according to research conducted by a team led by Cedric Annweiler, MD, PhD, at the Angers University Hospital in France.

Similarly, investigators led by Yelena Slinin, MD, MS, at the VA Medical Center in Minneapolis found that low vitamin D levels among older women are associated with higher odds of global cognitive impairment and a higher risk of global cognitive decline.

Slinin’s group based its analysis on 6,257 community-dwelling older women who had vitamin D levels measured during the Study of Osteopathic Fractures and whose cognitive function was tested by the Mini-Mental State Examination and/or Trail Making Test Part B.

Very low levels of vitamin D (less than 10 nanograms per milliliter of blood serum) among older women were associated with higher odds of global cognitive impairment at baseline, and low vitamin D levels (less than 20 nanograms per milliliter) among cognitively-impaired women were associated with a higher risk of incident global cognitive decline, as measured by performance on the Mini-Mental State Examination.

Annweieler’s team’s findings were based on data from 498 community-dwelling women who participated in the Toulouse cohort of the Epidemiology of Osteoporosis study.

Among this population, women who developed Alzheimer’s disease had lower baseline vitamin D intakes (an average of 50.3 micrograms per week) than those who developed other dementias (an average of 63.6 micrograms per week) or no dementia at all (an average of 59.0 micrograms per week).

These reports follow an article published in the Journals of Gerontology Series A earlier this year that found that both men and women who don’t get enough vitamin D — either from diet, supplements, or sun exposure — may be at increased risk of developing mobility limitations and disability.

(Photo Credit: Paul Burns / Getty Images)

Men and women explore the visual world differently

Everyone knows that men and women tend to hold different views on certain things. However, new research by scientists from the University of Bristol and published in PLoS ONE indicates that this may literally be the case.
Researchers examined where men and women looked while viewing still images from films and pieces of art. They found that while women made fewer eye movements than men, those they did make were longer and to more varied locations.

These differences were largest when viewing images of people. With photos of heterosexual couples, both men and women preferred looking at the female figure rather than the male one. However, this preference was even stronger for women.

While men were only interested in the faces of the two figures, women’s eyes were also drawn to the rest of the bodies - in particular that of the female figure.

Felix Mercer Moss, PhD student in the Department of Computer Science who led the study, said: “The study represents the most compelling evidence yet that, despite occupying the same world, the viewpoints of men and women can, at times, be very different.

“Our findings have important implications for both past and future eye movement research together with future technological applications.”

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In this schematic, reduced activation in discrete medial prefrontal brain regions is depicted (in blue) in schizophrenia patients, occurring 0.2 seconds after sound changes (top panel), cascading forward to widespread brain regions associated with the automatic activation of attentional networks 0.1 second later (bottom panel).

In Schizophrenia Patients, Auditory Cues Sound Bigger Problems

Researchers at the University of California, San Diego School of Medicine and the VA San Diego Healthcare System have found that deficiencies in the neural processing of simple auditory tones can evolve into a cascade of dysfunctional information processing across wide swaths of the brain in patients with schizophrenia.

The findings are published in the current online edition of the journal Neuroimage.

Schizophrenia is a mental disorder characterized by disturbed thought processes and difficulty in discerning real from unreal perceptions. Common symptoms include auditory hallucinations and unfounded suspicious ideas. The disorder affects about 1 percent of the U.S. population, or roughly 3 million people.

“Impairments in the early stages of sensory information processing are associated with a constellation of abnormalities in schizophrenia patients,” said Gregory Light, PhD, associate professor of psychiatry at UC San Diego and senior author of the study.

These impairments, according to Light, may explain how schizophrenia patients develop clinical symptoms such as hearing voices that others cannot hear and difficulty with cognitive tasks involving attention, learning and recalling information. “If someone’s brain is unable to efficiently detect subtle changes in sounds despite normal hearing, they may not be able to automatically direct their attention and rapidly encode new information as it is being presented.”

Light and colleagues used electroencephalography – a technique that records patterns of electrical brain activity using electrodes positioned on the scalp – on 410 schizophrenia patients and 247 nonpsychiatric comparison subjects. The researchers employed novel computational imaging approaches to deconstruct the brain dynamics that underlie two leading neurobiological markers used in schizophrenia research: mismatch negativity (MMN) and P3a event-related potentials.

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