Brain cell membranes have established “doorways” that accept or reject molecules trying to pass into the cell, researchers have founbd. The discovery fundamentally changes how researchers think about the behavior of neurons. It had been long believed that surface molecules such as receptors are enveloped right where they rest in the fatty membrane, to be drawn into the cell’s interior.
Researchers have discovered a gene mutation that causes a condition apparently identical to Huntington’s Disease, helping explain why some people with the disorder do not have a separate mutation found in most cases. The finding may help reveal why some diseases, like Huntington’s, Alzheimer’s and Parkinson’s, destroy some brain cells while sparing others. “For all practical purposes this is Huntington’s Disease, yet it’s caused by a different mutation on a completely different chromosome,” said Russell L. Margolis, M.D., associate professor of Psychiatry at Hopkins and director of the Johns Hopkins Laboratory of Genetic Neurobiology. “This is a rare version of an already rare disorder, but the mutation that causes it may not only help us better understand Huntington’s Disease, but could boost our understanding of many other neurodegenerative disorders.”
Researchers may have discovered the mechanism behind how prions ? pieces of protein molecules? can kill nerve cells in the brain and lead to some serious degenerative diseases. The key seems to lie in how one particular protein misfolds within an organelle inside the cell, transforming itself into a new agent and then poisoning the neuron in which it was made.
Results of an animal study published in the journal Science raise the possibility that the use of the rave fave drug Ecstasy ? methylene-dioxymethamphetamine ? can damage brain cells. The same cells, in fact, that are destroyed by Parkinson?s disease.
“We don’t know if human beings develop the same effects we describe in monkeys and in baboons,” Dr. George Ricaurte, a Johns Hopkins neurologist, told Reuters. “The broader issue is, are there hundreds of cases of unexplained parkinsonism in MDMA users? We don’t know because we haven’t looked.”
The Reuters article also contains the following quotation, reproduced below only marginally out of context: “[A]s you might imagine, it is not easy to get a baboon to take an oral dose of a drug.”
A single gene change that boosts the amount of a certain protein in early brain cells causes mice to develop abnormally large brains, Reuters Health reports. Normal mice have smooth, flat brains. But tinker with the gene in question and suddenly the little furballs develop brains so big they fold in on themselves, forming the wrinkles, ridges and crevices found also in the human brain. Study author Dr. Anjen Chenn of Brigham and Women’s Hospital and Harvard University in Boston said the finding might help researchers understand how humans came to develop brains so much bigger than those of other mammals. Whether or not more size means more smarts is uncertain, Chenn said. “It is quite an interesting question … and that’s something we want to look at in the future.”