Brain

TORONTO, April 25, 2014—Almost half of all homeless men who took part in a study by St. Michael's Hospital had suffered at least one traumatic brain injury in their life and 87 per cent of those injuries occurred before the men lost their homes.

While assaults were a major cause of those traumatic brain injuries, or TBIs, (60 per cent) many were caused by potentially non-violent mechanisms such as sports and recreation (44 per cent) and motor vehicle collisions and falls (42 per cent).

MADISON, Wis. – Marital stress may make people more vulnerable to depression, according to a recent study by University of Wisconsin-Madison researchers and their colleagues.

The long-term study, published in the April 2014 Journal of Psychophysiology, shows that people who experience chronic marital stress are less able to savor positive experiences, a hallmark of depression. They are also more likely to report other depressive symptoms.

TORONTO, April 25, 2014—Almost half of all homeless men who took part in a study by St. Michael's Hospital had suffered at least one traumatic brain injury in their life and 87 per cent of those injuries occurred before the men lost their homes.

While assaults were a major cause of those traumatic brain injuries, or TBIs, (60 per cent) many were caused by potentially non-violent mechanisms such as sports and recreation (44 per cent) and motor vehicle collisions and falls (42 per cent).

JUPITER, FL – April 25, 2014 – Scientists have known that abnormal brain growth is associated with autism spectrum disorder. However, the relationship between the two has not been well understood.

Now, scientists from the Florida campus of The Scripps Research Institute (TSRI) have shown that mutations in a specific gene that is disrupted in some individuals with autism results in too much growth throughout the brain, and yet surprisingly specific problems in social interactions, at least in mouse models that mimic this risk factor in humans.

The optic radiation is a dense fiber tract that emerges from the lateral geniculate nucleus and continues to the occipital visual cortex. Especially, the optic radiation is an important fiber structure that conveys visual information from the lateral geniculate nucleus to the primary visual cortex in the occipital lobe. Current studies have focused on the anatomical characteristics of optic radiation fiber tracts in individual brains and on comparisons of the anatomical characteristics of the optic radiation fiber tracts between patient and control groups.

Have you ever accidently missed a red light or a stop sign? Or have you heard someone mention a visible event that you passed by but totally missed seeing?

"When we have different things competing for our attention, we can only be aware of so much of what we see," said Kyle Mathewson, Beckman Institute Postdoctoral Fellow at the University of Illinois. "For example, when you're driving, you might really be concentrating on obeying traffic signals."

PHILADELPHIA – A new study suggests that targeting B cells, which are a type of white blood cell in the immune system, may be associated with reduced disease activity for people with multiple sclerosis (MS). The study is released today and will be presented at the American Academy of Neurology's 66th Annual Meeting in Philadelphia, April 26 to May 3, 2014.

A substantial proportion of risk for developing autism spectrum disorders (ASD), resides in genes that are part of specific, interconnected biological pathways, according to researchers from the Icahn School of Medicine at Mount Sinai, who conducted a broad study of almost 2,500 families in the United States and throughout the world. The study, titled "Convergence of Genes and Cellular Pathways Dysregulated in Autism Spectrum Disorders," was first published online in the American Journal of Human Genetics on April 24.

Suicide is a general risk for people with psychosis. According to the Journal of Psychiatry, 20 percent to 40 percent of those diagnosed with psychosis attempt suicide, and up to 10 percent succeed.

And teens with psychotic symptoms are nearly 70 times more likely to attempt suicide than adolescents in the general population, according to a 2013 study in JAMA Psychiatry.

But what contributes to such high numbers?

Nearly a decade ago, the era of optogenetics was ushered in with the development of channelrhodopsins, light-activated ion channels that can, with the flick of a switch, instantaneously turn on neurons in which they are genetically expressed. What has lagged behind, however, is the ability to use light to inactivate neurons with an equal level of reliability and efficiency.

Scientists have bioengineered, in neurons cultured from rats, an enhancement to a cutting edge technology that provides instant control over brain circuit activity with a flash of light. The research funded by the National Institutes of Health adds the same level of control over turning neurons off that, until now, had been limited to turning them on.

STANFORD, Calif. — In 2005, a Stanford University scientist discovered how to switch brain cells on or off with light pulses by using special proteins from microbes to pass electrical current into neurons.

Since then, research teams around the world have used the technique that this scientist, Karl Deisseroth, MD, PhD, dubbed "optogenetics" to study not just brain cells but heart cells, stem cells and the vast array of cell types across biology that can be regulated by electrical signals — the movement of ions across cell membranes.

HOUSTON – (April 24, 2014) – A team of international scientists led by Baylor College of Medicine has discovered a novel gene (CLP1) associated with a neurological disorder affecting both the peripheral and central nervous systems. Together with scientists in Vienna they show that disturbance of a very basic biological process, tRNA biogenesis, can result in cell death of neural progenitor cells. This leads to abnormal brain development and a small head circumference as well as dysfunction of peripheral nerves.

Johns Hopkins researchers report that they have identified a protein essential to the formation of the tiny brain region in mice that coordinates sleep-wake cycles and other so-called circadian rhythms.

By disabling the gene for that key protein in test animals, the scientists were able to home in on the mechanism by which that brain region, known as the suprachiasmatic nucleus or SCN, becomes the body's master clock while the embryo is developing.

PHILADELPHIA - Amita Sehgal, PhD, a professor of Neuroscience at the Perelman School of Medicine, University of Pennsylvania, describes in Cell a circuit in the brain of fruit flies that controls their daily, rhythmic behavior of rest and activity. The new study also found that the fly version of the human brain protein known as corticotrophin releasing factor (CRF) is a major coordinating molecule in this circuit. Fly CRF, called DH44, is required for rest/activity cycles and is produced in cells that receive input from the clock cells in the fly brain.