Olfactory bulbectomy depresses ultrasound production and scent marking by female hamsters

Female hamsters were observed for rates of ultrasound production, vaginal marking and flank marking before and after bilateral olfactory bulbectomy, unilateral bulbectomy or sham operations. Unilaterally bulbectomized and sham-operated subjects maintained preoperative levels of each behavior. In contrast, females with bilateral olfactory bulbectomies showed consistent decreases in rates of vocalization and scent marking. These results emphasize the dependence on an intact olfactory system of several courtship or agonistic behaviors that affect hamster reproduction by functioning as noncontact communications. Together with the results of previous studies suggesting that lordosis by female hamsters is unaffected by olfactory bulbectomy, these data also suggest differences in the brain and sensory mechanisms that control distinct types of reproductive behavior.