WOLF, Mary C; DALY, Kevin C; MOORE, Paul A; Bowling Green State University; West Virginia University; Bowling Green State University : Central nervous system processing of odor stimuli: the effect of stimulus duration on information coding

Two major issues facing sensory ecologists are how olfactory information is coded in the nervous system and how that information correlates with behavior. Results from our lab indicate that crayfish orientation behavior is sensitive to temporal components of an odor signal. Due to this temporal sensitivity, we expect to find neural correlates within the olfactory system that underlie the organism�s behavior. In the present study, we investigated how the temporal aspects of an odor signal are processed in the central nervous system of the crayfish. Neural ensemble recordings were made on an isolated head preparation perfused with oxygenated crayfish saline. Silicon multichannel electrode arrays were inserted into the deutocerebrum of the crayfish brain. The medial antennule was placed into an olfactometer and stimulated with 3 types of stimuli: glutamine, glycine, and shrimp extract. The stimuli were presented at a specific molar concentration (10-5 M) and inter-pulse interval (5000 ms), varying only the duration of the odor pulses presented to the antennule. Our results suggest that there are coordinated clusters of units that collectively produced stimulus-dependent responses that were further dependent on stimulus duration. These results are consistent with our behavioral data demonstrating that crayfish orientation is sensitive to the temporal dynamics of odor plumes.