Gene may be key to evolution of larger human brain

Researchers have identified a gene that appears to have played a role in the expansion of the human brain’s cerebral cortex — a hallmark of the evolution of humans from other primates. By comparing the gene’s sequence in a range of primates, including humans, as well as non-primate mammals, the scientists found evidence that the pressure of natural selection accelerated changes in the gene, particularly in the primate lineage leading to humans.

Ancient DNA mutations permitted humans to adapt to colder climates

How did early humans who migrated from Africa survive in the colder climates of Europe, Asia and the New World? According to a new study, it may be the same reason some people today are more prone to obesity, Alzheimer’s disease and the effects of aging. A research team in California reports that key mutations in the mitochondrial DNA (mtDNA) of human cells may have helped our migrating ancestors adapt to more northerly climates, and ultimately link people with this ancestral history to specific diseases.

‘Bad guy’ in stroke brain damage turns out to be good

In experiments in the laboratory and with mice, the Johns Hopkins researchers found that the chemical prostaglandin-E2 protects brain cells from damage. The finding was completely unexpected, the researchers say, because prostaglandin-E2 causes damage in other tissues and is made by an enzyme, COX-2, known to wreak havoc in the brain after injury. The findings appear in the Jan. 7 issue of the Journal of Neuroscience.

Morning headaches associated with depression, anxiety disorders

Morning headaches affect about one person in 13 in the general population and are associated with depression and anxiety disorders, according to an article in the January 12 issue of The Archives of Internal Medicine, one of the JAMA/Archives journals. According to the article, waking up with a headache is traditionally associated with sleep disorders. Studies have reported a high association between morning headache and obstructive sleep apnea syndrome, and snoring. The prevalence of morning headache in the general population is not known, although according to a Swedish study, 5 percent of the population often experiences morning headache.

Researchers seek to clone ‘mad cow disease’ resistant cattle

Scientists are trying to clone cattle that are genetically incapable of developing “Mad Cow Disease.” As federal and state government officials grapple with strategies to limit the economic and health risks associated with the troublesome discovery of the nation’s first case of Bovine Spongiform Encephalopathy (BSE) ? or “Mad Cow Disease”– scientists in Virginia are conducting important research with the little understood molecules believed to cause the deadly brain-wasting disease.

Enzyme Degrades Mad Cow Disease Prion

Research has shown that, under proper conditions, an enzyme can fully degrade the prion — or protein particle — believed to be responsible for mad cow disease and other related animal and human diseases. These transmissible prions believed to be the cause of bovine spongiform encephalopathy (BSE), the technical name for mad cow disease, are highly resistant to degradation. But the new research, which tested the effects of a bacterial enzyme keratinase on brain tissues from cows with BSE and sheep with scrapie, showed that, when the tissue was pretreated and in the presence of a detergent, the enzyme fully degraded the prion, rendering it undetectable.

Nanotubes could make better brain probes

Researchers have shown that extremely thin carbon fibers called “nanotubes” might be used to create brain probes and implants to study and treat neurological damage and disorders. Probes made of silicon currently are used to study brain function and disease but may one day be used to apply electrical signals that restore damaged areas of the brain. A major drawback to these probes, however, is that they cause the body to produce scar tissue that eventually accumulates and prevents the devices from making good electrical contact with brain cells called neurons.

Pioneering brain implants for deaf people

Two deaf women in the US have become the first people to undergo the risky procedure of having implants in their brainstems, New Scientist reports.

The devices are designed to restore hearing by directly stimulating nerves. Some deaf people have been given implants that sit just outside the brainstem, but these do not work very well.

Feeding auditory signals directly into the brainstem should work better, but because the brainstem carries signals from the entire body to the brain, any damage caused by an implant could be disastrous.

The procedure is far more risky than, say, placing implants in the cortex to try to restore some vision. “If you damage the cortex it’s not that big a deal. But at the brainstem level every neuron you damage could damage function,” says Bob Shannon of the House Ear Institute in Los Angeles, the surgeon who pioneered the procedure. “We took 15 years to convince ourselves that this could be done safely.”

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Friendships play key role in suicide thoughts of girls, but not boys

Relationships with friends play a significant role in whether teenage girls think about suicide, but have little impact on suicidal thoughts among boys, according to a new nationwide study. The research found that girls were nearly twice as likely to think about suicide if they had only a few friends and felt isolated from their peers. Girls were also more likely to consider suicide if their friends were not friends with each other. These relationship factors had no significant effect on whether boys considered suicide.

Grape juice improved memory and neuro-motor skills in animal study

Consuming Concord grape juice significantly improved laboratory animals’ short-term memory in a water maze test as well as their neuro-motor skills in certain of the coordination, balance and strength tests, according to preliminary research presented at the 1st International Conference on Polyphenols and Health recently held in Vichy, France.