The finding provides an important insight into the mechanisms that regulate the sensitivity of brain cells to neurotransmitters, the chemical messengers that the cells use to communicate with one another.
"Learning how neurons respond to neurotransmitters is important not only to understanding basic brain functioning, but also may one day lead to new insight into a variety of new therapies," said Duane Alexander, Director of the NICHD.
Like a key fits into a lock, neurotransmitters fit into specific sites, or receptors, studding the surface of brain cells. In an elaborate relay system, a cell that is excited by one neurotransmitter will, in turn, release neurotransmitters of its own. These affect still other cells, which, in turn, release more neurotransmitters, and so on. In this way, messages are transmitted throughout the brain's various mental circuits.
The researchers studied one of the glutamate receptors, found throughout the brain and involved in numerous learning and memory processes. Whether in the brain or in laboratory cultures, many receptors show reduced activity when exposed to higher-than-normal amounts of a neurotransmitter, a process called desensitization. Essentially, the cells become less sensitive to the effects of neurotransmitters.
According to an NICHD author of the paper, Mark Mayer, head of the Laboratory of Cellular and Molecular Neurophysiology, the researchers biochemically isolated one part of the glutamate receptor and determined its structure at the atomic level. They then designed altered, or mutant, receptors and determined their atomic structures as well. By observing ho
Contact: Bob Bock
NIH/National Institute of Child Health and Human Development