The purpose of this application is to provide the PI with resources that will enable him to acquire technical skills and expertise in molecular and cell biology. The PI is a Professor in the Departments of Physiological Science and Neurobiology at UCLA. During most of his scientific career the PI has studied the neural basis of simple forms of learning and memory in invertebrate organisms. The PI is highly trained in electrophysiological techniques for investigating learning-related neuronal plasticity, as well as in behavioral techniques for investigating simple forms of invertebrate learning and memory. Recent data from the laboratory of the PI indicates that the endogenous monoamine, serotonin (5-HT), modulates the intracellular trafficking of AMPA-type glutamate receptors in motor neurons of the marine snail Aplysia californica. Additional data from the Pl's laboratory suggests that 5-HT-induced modulation of AMPA-type receptor trafficking contributes to behavioral sensitization in Aplysia. To elucidate the potential cellular mechanisms of 5-HT-induced modulation of AMPA-type receptor trafficking in Aplysia, the PI wishes to acquire research skills in cellular and molecular biology. Specifically, during the award period the PI will undertake the following research projects: (i) to clone and sequence ionotropic glutamate receptor genes from the Aplysia nervous system; (ii) to perform in situ hybridization to localize the mRNAs of the cloned glutamate receptors in the Aplysia CNS; (iii) to express the Aplysia glutamate receptors in Xenopus oocytes for biophysical and pharmacological characterization of the expressed receptor channels; (iv) to generate antibodies to the different glutamate receptor subunits for use in immunohistochemical studies of the effect of 5-HT on the distribution of the receptors; and iv) to test whether expression of the glutamate receptor is enhanced in motor neurons of Aplysia during a form of long-term memory, long-term sensitization. To develop the technical expertise required for these projects, the PI will collaborate with several UCLA colleagues. The proposed collaborators are all highly knowledgeable and experienced in the molecular and cell biological techniques necessary for completing the proposed research. Furthermore, the laboratories of the collaborators have the necessary equipment for the proposed research.