Normal and abnormal development of the antennal lobes in M. sexta, page 2
In some animals, a small subset of glomeruli are specialized for processing information about specific social odors, pheromones. We have focused on one such group of glomeruli, the macroglomerular complex (MGC), which is responsible for processing information about the female sex-attractant pheromone in the brain of the male moth. Previous studies have suggested that individual glomeruli may act as discrete functional units for odor processing, however, the role of glomeruli in the processing of olfactory information is still poorly understood. We are interested in how the presence (or absence) of glomeruli in the antennal (olfactory) lobe of the brain in the moth M. sexta is related to the processing of olfactory information, and the performance of odor-modulated behaviors. We are able to ask these questions about antennal lobe function because previous work in the laboratory of Dr. Leslie Tolbert, also faculty in the Arizona Research Labs Division of Neurobiology, has shown that level of glomerular development in the mothıs antennal lobe depends on how many odor receptor cells grow into the brain from the antennae during pupal development. By surgically removing 80-90% of the antennae right after the caterpillars become pupae we can cause the development of adult moths with few or no glomeruli in the antennal lobes of their brains. Using these experimentally generated animals, we have asked the question "Are the presence of anatomically identifiable glomeruli necessary to support olfactory-mediated behavior?" We have challenged moths to fly upwind to sources of attractive odors in our laboratory wind tunnel and surprisingly found that at least some experimental moths flew upwind toward a source of attractive odor (females to host plant; males to female sex-pheromone), thus indicating that they could detect and process olfactory stimuli. |