Dr. Reppert's laboratory has made fundamental contributions in understanding developing circadian rhythmicity and has recently directed research activities towards investigating the neurobiology of melatonin action at a cellular nd biochemical level. The pineal hormone melatonin has been shown to influence circadian rhythms in a variety of species, including humans, and has important influences on reproduction in certain mammalian species The proposed experiments are designed to increase our understanding of melatonin action and will employ contemporary biochemical approaches. The experiments will provide a setting for collaboration with experts in neurochemistry, immunology, and receptor and G protein research. Lizard and chick brain membranes, rich sources of melatonin receptors, will be used to characterize receptors that trigger physiologic responses to melatonin. It is proposed to (1) develop methods for identifying melatonin receptors. (2) purify solubilized melatonin receptors, and (3) further examine receptor-G protein interactions. Using partially purified receptors (4) monoclonal antibodies will be develop against melatonin receptors. (5) These antibodies will be used to identify specific neuronal populations with melatonin receptors and will also be used to examine the subcellular localization of melatonin receptors. Long-term objectives include understanding the molecular mechanisms of melatonin action.
