Meeting Abstract

P3.105  Wednesday, Jan. 6  Modulatory influences of anterior cerebral neurons on fictive swimming in Melibe leonina MCPHERSON, Duane R; SUNY at Geneseo mcpherso@geneseo.edu

The opisthobranch mollusc Melibe leonina swims by rhythmic lateral bending of the body, and the swim movements are driven by a central pattern-generating circuit located in the central ganglia of the nervous system. The isolated central ganglia (pedal and cerebropleural ganglia) can spontaneously produce the neural analog of swimming (fictive swimming). In this study I explored the influence of neurons in the anterior region of the cerebral ganglia on neurons in the pedal ganglia, including putative motoneurons (neurons having peripheral axons and/or firing in stable relation to pedal nerve activity during fictive swimming). A number of anterior cerebral neurons were found to have mild excitatory effects on pedal neurons, and these effects appeared to be indirect. In preparations that exhibited fictive swimming, some anterior cerebral neurons were found which enhanced the rhythmicity of the motor activity. Some of these cerebral neurons were themselves rhythmically active in stable phase relation to pedal nerve activity. Thus, they may be linked to the swim pattern-generating neural circuit. Supported by a Mid-Career Summer Fellowship from the SUNY Geneseo Research Foundation.