The ferret's vomeronasal organ and accessory olfactory bulb: Effect of hormone manipulation in adult males and females

The male ferret, a carnivore, was recently shown to possess a vomeronasal o rgan (VNO). We compared the morphology of the VNO and its associated access ory olfactory bulb (AOB) in male and female ferrets that were killed in adu lthood. The volume and surface area of the VNO neuroepithelium were similar in adult gonadectomized male and female ferrets regardless of whether they were treated with testosterone propionate (TP) or oil vehicle. An AOB was localized bilaterally in the medial caudal part of the olfactory bulbs of a dult ferrets using soybean agglutin binding and immunostaining for luteiniz ing hormone-releasing hormone and tyrosine hydroxylase as well as Nissl sta ining of coronal, horizontal, and sagittal brain sections. There was no eff ect of sex or TP treatment on AOB cell layer volume in adult gonadectomized animals. We found the ferret's AOB to be more medially located and much sm aller than previously reported in this species, thus highlighting the impor tance of using several histochemical markers to characterize this structure in any previously unexamined species. Adult male and female ferrets both h ave a VNO and an associated AOB. More research is needed to determine what role, if any, this accessory olfactory system plays in mediating behavioral and neuroendocrine responses to pheromones in ferrets of either sex. Anat Rec 263:280-288, 2001. (C) 2001 Wiley-Liss, Inc.