Sex Difference and Testosterone Modulation: DISCUSSION(1)

19 Mar

Pheromones Are Processed by the Main Olfactory System in Ferrets

In experiment 3, both male and female ferrets spent significantly more time investigating soiled than clean bedding. This finding suggests that pheromones emitted by urine, feces, and sebaceous glands may be used by ferrets to mark territory and to attract or repel conspecifics. The results of experiments 1 and 2 suggest that in ferrets of both sexes the pheromones derived from estrous females as well as from breeding males are detected by receptors in the MOE, whereupon signals are passed to the MOB. Information is then conveyed to the MA and then on to the BNST, mPOA, and/or VLH in a manner that varies with the source of the pheromones (male versus female) and the sex of the subject. birth control yasmin

In contrast to their effects in the MOB, pheromones failed to stimulate neuronal Fos-IR in the ferret’s AOB. This absence of response in ferrets contrasts with results from rats, hamsters, voles, and mice, in which pheromones derived from soiled bedding, urine, or vaginal secretions readily stimulated neuronal Fos-IR in the AOB granule and mitral cell layers. The absence of an AOB neuronal Fos response in the present studies using ferrets cannot, by itself, be taken as absolute proof that VNO receptors were not activated by the pheromones presented. All subjects were killed 90 min after the onset of odor presentation, and it is possible that the timing of neuronal Fos-IR induction in the AOB somehow differs from that seen in other brain regions. In a study using male hamsters, pheromones from female hamster vaginal secretions augmented neuronal Fos-IR simultaneously in the MOB and AOB 60 min later.