The long term objectives of the research program are to obtain detailed information about processes of release of neurotransmitters at synapses in the vertebrate central nervous system, and about the interactions of transmitters with the postsynaptic nerve cell membrane. Detailed knowledge about these processes at the molecular level is important if we are to understand how information is processed by the nervous system and how defects in nervous system function arise. For the next grant period there are four specific aims. 1. To characterize further the membrane channels activated by glycine and Gamma-aminobutyric acid (GABA) in the vertebrate central nervous system. Experiments will involve noise analysis and patch-clamp techniques, applied to Muller cells in the brainstem of the lamprey. 2. To determine the characteristics of excitatory postsynaptic channels in the vertebrate nervous system activated by glutamate, again using the lamprey brain as a model system. 3. To assay amino acids released from the lamprey brainstem by nerve stimulation and potassium depolarization in the presence of calcium in order to determine which substances, such as glycine or glutamate, are candidates for neurotransmitters. 4. To examine the processes involved in hormone release by primary pituitary cells in culture. In particular, the nature of the membrane changes produced by secretagogues will be examined, as well as the nature of the inhibitory channels activated by dopamine.