A new drug can block the symptoms of schizophrenia as in rats without apparent side effects. The work, described in Science tomorrow , suggests a new approach to drugs for schizophrenia that may one day lead to better therapies for the disease, which affects 1% of the population of the United States only.
These drugs are sorely lacking. Current drugs against schizophrenia, known as neuroleptics, are designed to relieve the symptoms of the disease by blocking the action of a brain chemical signal, dopamine. But as patients who take the often see reductions of paranoia and hallucinations, medications provide little relief of other symptoms, such as poor attention spans, confused thoughts, and difficulty interacting with other people. In addition, neuroleptics often cause disturbing side effects, including uncontrollable tremors similar to Parkinson's patients
Phencyclidine of psychoactive substances, or PCP, offered tempting tips that a different approach could to work:. Blocking the activity of another neurotransmitter called glutamate. PCP induces symptoms of schizophrenia as in healthy people. Following these observations, neuroscientists Bita Moghaddam and Barbara Adams of Yale University School of Medicine and the Veterans Administration Medical Center in West Haven, Connecticut, PCP administered to rats who develop symptoms such as the frenzied race and turn his head thought parallel psychotic symptoms in humans, and examined what happens to the brain glutamate levels in animals. Although previous work has suggested that they should go down in response to the CFP, Yale workers found instead they jumped. Moghaddam then speculated, she recalls, that "if we block the activation of glutamate, maybe we can block these behavioral effects."
To avoid side effects, Moghaddam and Adams wanted to block the glutamate activity in the parts of the brain where it can be high. So, they turned to a drug called LY354740, which is under development at Eli Lilly & Co. in Indianapolis for other psychiatric disorders such as anxiety. By binding to metabotropic receptor called glutamate on nerve endings glutamatergic releasing LY354740 dampens the output of the transmitter, but only when the too high. when Moghaddam and Adams rats given the drug before Lilly administer the CFP, they found that glutamate levels went up in the prefrontal cortex, one of the regions of the brain that breaks down in schizophrenia. the six LY354740-treated rats also remained calm and showed little behavior nods, compared with controls who received only CFP.
Encouraging results in rats do not guarantee that the approach will work in humans. Yet, says Horvitz Jon schizophrenia researcher at Columbia University in New York, "it's an awesome job. This is a promising way to a drug that alleviates the symptoms of schizophrenia."
0 Komentar