9511020 Adams Nerve cells communicate with each other by means of chemical signals called neurotransmitters and neurohormones. The arrival of electrical impulses at nerve endings release tiny amounts of neurotransmitters acting locally or much larger amounts of neurohormones acting at longer distances; both stimulate the electrical activity in neighboring nerve cells. The release of these chemical signals depends on the brief entry of calcium to nerve terminals, a process that is highly regulated by "calcium channels". Small amounts of calcium enter for neurotransmitter release, whereas larger and longer periods of calcium entry are necessary for the release of hormones. These differences are to a large extent dictated by variations in the properties of different calcium channels. Dr. Adams and his colleagues are working to define the properties of calcium channels in different types of nerve cells, ranging from motoneurons to neuroendocrine cells, using a combination of electrophysiology and pharmacology. The kinetics of calcium channel opening and closing as well as their sensitivities to different drugs and toxins will be used to classify them into different groups and to associated them with different functions in nerve cells. Potential applications of these studies are the development of pharmaceuticals and pest control agents.
