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

Abstract

The male ferret, a carnivore, was recently shown to possess a vomeronasal organ (VNO). We compared the morphology of the VNO and its associated accessory olfactory bulb (AOB) in male and female ferrets that were killed in adulthood. 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 adult ferrets using soybean agglutin binding and immunostaining for luteinizing hormone-releasing hormone and tyrosine hydroxylase as well as Nissl staining of coronal, horizontal, and sagittal brain sections. There was no effect 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 smaller than previously reported in this species, thus highlighting the importance of using several histochemical markers to characterize this structure in any previously unexamined species. Adult male and female ferrets both have 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.

Site-specific effects of anosmia and cloacal gland anesthesia on Fos expression induced in male quail brain by sexual behavior

“…This method has been validated in previous studies in birds [50,68,69] and in mammals [52]. We confirmed that blockade of the nostrils suppresses nearly completely the well-characterized behavioral reactions to acetic acid and therefore presumably its detection.…”

“…All these experiments found that dysfunctions of the olfactory epithelium produce major decrements in sexual behavior similar to those observed after olfactory bulbectomy. However, other experiments have produced contradictory results in male hamsters [71], dogs [45], ferrets [52], cats [4] and rhesus monkeys [41,61] in which peripheral anosmia failed to disrupt sexual behavior. These discrepancies could be related to the previous sexual experience of the subject that might mitigate the disruptive effects of olfactory deprivation on male sexual behavior as is clearly the case in male hamster [66,86].…”

Expression of neuron‐specific markers by the vomeronasal neuroepithelium in six species of primates

“…Compared to rodent VNO, the histology of the primate VNO is more similar to that of goats (Takigami et al, 2000), sheep (Cohen-Tannoudji et al, 1989), swine (Dorries et al, 1997), and ferrets (Weiler, et al, 1999). In the last three of these species, the VNO is not involved in all of the functions mediated by the rodent VNO (CohenTannoudji et al, 1989;Dorries et al, 1997;Weiler, et al, 1999;Kelliher et al, 2001). Likewise, several behaviors that in rodents are mediated by the VNO are not solely VNO-mediated in primates (Barrett et al, 1993;Aujard, 1997;Kraus et al, 1999).…”

Distribution of Protein Gene Product 9.5-Immunopositive and NADPH-Diaphorase-Positive Neurons in the Common Marmoset (Callithrix jacchus) Accessory Olfactory Bulb

“…On the other hand, the granule cells, the inhibitory interneurons of the AOB, modulate the excitation of the mitral/tufted cells [12]. Although the AOB has been identified in many mammalian species, the precise position of the AOB was recently demonstrated in the ferret [8] and dog [17]. Since the AOB of the ferret and dog is small in size and different in morphology and the position from the rodents, the AOB of these animals has been overlooked.…”

“…Since the AOB of the ferret and dog is small in size and different in morphology and the position from the rodents, the AOB of these animals has been overlooked. The recent reports demonstrated the precise position of the dog and ferret AOB using selective histochemical markers for the AOB [8,17]. In these animals, however, the laminar structure of the AOB often remains to be solved even though the position of the AOB was clearly demonstrated.…”