Cells Reveal Brain Chemistry Secrets (via BBC News)
Scientists have developed biological cells that can give insight into the chemistry of the brain. The cells, which change colour when exposed to specific chemicals, have been used to show how a class of schizophrenia drug works…
Schizophrenia is most commonly associated with symptoms such as delusions and hallucinations. But people with the illness also struggle to sustain attention or recall information.
A class of drugs called atypical neuroleptics has become commonly prescribed, in part because they seem to improve these problems. However, the way they altered brain chemistry was uncertain.
It was known that the drugs trigger the release of a large amount of a chemical called acetylcholine, which enables brain cells to communicate with each other. However, the drugs have also been shown to hobble a receptor on the surface of the receiving cell, which would effectively block the message.
The San Diego team designed biological cells - called CNiFERs - which changed colour when acetylcholine latched onto this particular class of receptors - an event scientists have not previously been able to detect in a living brain.
They implanted the cells into rat brains, then stimulated a deeper part of the brain in a way known to release acetylcholine nearby.
In response, CNiFERs changed colour - proving that they were working.
They then gave the rats one of two atypical neuroleptics. In both cases the drug severely depressed the response from the CNiFERs. This suggested that the drugs’ receptor-blocking action over-rides the increase they trigger in acetylcholine.
Lithium in water 'curbs suicide'
Drinking water which contains the element lithium may reduce the risk of suicide, a Japanese study suggests. Researchers examined levels of lithium in drinking water and suicide rates in the prefecture of Oita, which has a population of more than one million. The suicide rate was significantly lower in those areas with the highest levels of the element, they wrote in the British Journal of Psychiatry.
High doses of lithium are already used to treat serious mood disorders. But the team from the universities of Oita and Hiroshima found that even relatively low levels appeared to have a positive impact of suicide rates. Levels ranged from 0.7 to 59 micrograms per litre. The researchers speculated that while these levels were low, there may be a cumulative protective effect on the brain from years of drinking this tap water…. (continues @ BBC News)
Forget It! A Biochemical Pathway For Blocking Your Worst Fears?
A receptor for glutamate, the most prominent neurotransmitter in the brain, plays a key role in the process of “unlearning,” report researchers at the Salk Institute for Biological Studies….
“Most studies focus on ‘learning,’ but the ‘unlearning’ process is probably just as important and much less understood,” says Stephen F. Heinemann, Ph.D., a professor in the Molecular Neurobiology Laboratory, who led the study. “Most people agree that failure to ‘unlearn’ is a hallmark of post-traumatic stress disorders and if we had a drug that affects this gene it could help soldiers coming back from the war to ‘unlearn’ their fear memories….”
Heinemann and his team were particularly interested in whether mGluR5, short for metabotropic glutamate receptor 5, which had been shown to be involved in several forms of behavioral learning, also plays a role in inhibitory learning. “Inhibitory learning is thought to be a parallel learning mechanism that requires the acquisition of new information as well as the suppression of previously acquired experiences to be able to adapt to novel situations or environments,” says Heinemann.
Toxoplasmosis Parasite May Trigger Schizophrenia And Bipolar Disorders
Toxoplasmosis…is relatively common, with 10-20% of the UK population and 22% of the US population estimated to carry the parasite….
The parasite infects the brain by forming a cyst within its cells and produces an enzyme called tyrosine hydroxylase, which is needed to make dopamine. Dopamine’s role in mood, sociability, attention, motivation and sleep patterns are well documented and schizophrenia has long been associated with dopamine, which is the target of all schizophrenia drugs on the market.
