It might look small, but it’s got a lot to offer and it’s here to stay. I am of course talking about the Y chromosome, the stumpy partner of X. This comparatively meager looking chromosome has long been thought to play few roles aside from sex determination in mammals.
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.
Depression affects more than one out of three survivors of critical illness, according to a Vanderbilt study released in The Lancet Respiratory Medicine, and the majority of patients experience their symptoms physically rather than mentally.
“Myelin is a relatively recent invention during evolution,” says Arlotta. “It’s thought that myelin allowed the brain to communicate really fast to the far reaches of the body, and that it has endowed the brain with the capacity to compute higher-level functions.”
In fact, loss of myelin is a feature in a number of devastating diseases, including multiple sclerosis and schizophrenia. But the new research shows that despite myelin’s essential roles in the brain, “some of the most evolved, most complex neurons of the nervous system have less myelin than older, more ancestral ones,” said Arlotta, co-director of the HSCI neuroscience program.
She said the higher one looks in the cerebral cortex — closer to the top of the brain, which is its most evolved part — the less myelin one finds. Not only that, but “neurons in this part of the brain display a brand-new way of positioning myelin along their axons that has not been previously seen. They have ‘intermittent myelin’ with long axon tracts that lack myelin interspersed among myelin-rich segments.”
“Contrary to the common assumptions that neurons use a universal profile of myelin distribution on their axons, the work indicates that different neurons choose to myelinate their axons differently,” Arlotta said.
“In classic neurobiology textbooks, myelin is represented on axons as a sequence of myelinated segments separated by very short nodes that lack myelin. This distribution of myelin was tacitly assumed to be always the same, on every neuron, from the beginning to the end of the axon. This new work finds this not to be the case.”
The results of the research by Arlotta and postdoctoral fellow Giulio Srubek Tomassy, the first author on the report, are published in the latest edition of the journal Science.
Alzheimer's disease is the leading cause of dementia and affects some 400,000 people in Spain alone. However, no effective cure has yet been found. One of the reasons for this is the lack of knowledge about the cellular mechanisms which cause alterations in nerve transmissions and the loss of memory ...
A recently FDA-approved device has been shown to reduce seizures in patients with medication-resistant epilepsy by as much as 50 percent. When coupled with an innovative electrode placement planning system developed by physicians at Rush, the device facilitated the complete elimination of seizures in nearly half of the implanted Rush patients enrolled in the decade-long clinical trials.
The Yerkes National Primate Research Center, Emory has received a five-year, $9.5 million grant from the National Institute of Mental Health to establish a Silvio O. Conte Center in Neuroscience Research to study oxytocin, a brain chemical known for forming bonds between mother and baby.
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.
Howard Hughes Medical Institute (HHMI) scientists have used an analysis of channelrhodopsin's molecular structure to guide a series of genetic mutations to the ion channel that grant the power to silence neurons with an unprecedented level of...
Better-educated people appear to be significantly more likely to recover from a moderate to severe traumatic brain injury (TBI), suggesting that a brain’s “cognitive reserve” may play a role in helping people get back to their previous lives, new Johns Hopkins research shows.
A novel imaging technique provides insights into the role of redox signaling and reactive oxygen species in living neurons, in real time. Scientists have developed a new optical microscopy technique to unravel the role of 'oxidative stress' in healthy as well as injured nervous systems.