Abstracts - Deutsche Zoologische Gesellschaft

184 Neurobiology PostersP NB.28 - ENCaste- and sex-specific adaptations of the dual olfactory pathway in the brain of theant Camponotus floridanusChristina Zube, Wolfgang RösslerBehavioral Physiology and Sociobiology, Biozentrum, University of WürzburgOlfaction plays a key role in mediating ant behavior, and ant societies are characterized by caste- andsex-specific division of labor. We propose that caste- and sex-specific adaptations in the olfactorypathway promote differences in behavior. This study compares olfactory centers in the brain of large(major) workers, small (minor) workers, virgin queens, and males of the carpenter ant Camponotusfloridanus. The number of glomeruli in the antennal lobe was similar in the female castes, althoughthe glomerular volumes differed. Males had ~45% fewer glomeruli compared to females (~258 and~434) and one antennal sensory tract was absent, whereas a dual output pathway to the mushroombodies was present. In contrast to females, however, the number of glomeruli connected to the medialantennocerebral tract was substantially smaller than those associated with the lateral tract. Allglomeruli in the male antennal lobe contained serotonergic processes, whereas in the female castesglomeruli in the large tract six cluster lacked serotonergic innervations, but projection neurons ofthis cluster were responsive to stimulation with NO. We conclude that differences in general glomerularorganization are subtle among the female castes, but sex-specific differences in the number,connectivity and neuromodulatory innervation of glomeruli are substantial and likely to underliedifferences in olfactory processing and learning. Supported by DFG, SFB 554, TP A8