Lateral Olfactory Tract Transections Impair Discrimination of Individual Odors, Sex Odor Preferences, and Scent Marking In Female Golden Hamsters (Mesocricetus Auratus)

Abstract

Transections of the lateral olfactory tract (LOT), the major source of olfactory bulb efferents to posterior brain regions, have produced severe deficits in hamster sociosexual behavior in earlier studies. The present experiment examined the role of the LOT in (a) discrimination of individual odors, (b) sex odor preferences and (c) odor-elicited scent marking in female golden hamsters. LOT cuts at the level of the anterior olfactory tubercle greatly reduced overall investigation of social odors. LOT-lesioned females did not discriminate between the flank gland or urine scents of individual males in a habituation/discrimination task and eliminated the usual preference females show for male odors over female odors in a Y-maze. LOT cuts also virtually eliminated flank marking behavior but had relatively minor effects on vaginal marking. Thus, olfactory bulb connections with posterior neural structures via LOT fibers appear to be the primary substrate for social odor discrimination/recognition and flank marking behaviors by female hamsters. Vaginal marking, although decreased by LOT cuts, appears more strongly regulated by hormonal signals than by odor cues.