title: Sexual dimorphism in the vomeronasal system of the rabbit.
abstract: Studies have shown that the vomeronasal system (VNS), an olfactory neural network that participates in the control of reproductive physiology and behavior, is sexually dimorphic in the rat. These works have also shown two main characteristics of brain sexual dimorphism: (a) dimorphism appears in neural networks related to reproduction and (b) it can present two morphological patterns: one in which males present greater morphological measures than females (male > female) and another in which the opposite is true (female > male). The present work extends the hypothesis to the rabbit, as a representative species of Lagomorpha. In addition, the locus coeruleus (LC), which is known to send rich noradrenergic projections to VNS structures, was also studied. Sex differences were found in: (a) the number of mitral, and dark and light granule cells (female > male) of the accessory olfactory bulb (AOB); (b) the medial amygdala (Me) and its dorsal (Med) and ventral (Mev) subdivisions, males showing greater values than females in volume and number of neurons, while in the posteromedial cortical amygdala (PMCo or C(3)), females show greater density of neurons than males and (c) the posteromedial division of the bed nucleus of the stria terminalis (BSTMP) in which males have more neurons than females. No sex differences were seen in the bed nucleus of the accessory olfactory tract (BAOT) and the LC. These results evidence that, as it was observed in rodents, sex differences are also seen in the VNS of Lagomorpha and that these sex differences present the two morphological patterns seen in Rodentia. Differences between orders are discussed with respect to the species-specific physiological and behavioral peculiarities.
authors.affiliation: Departamento de Psicobiología, UNED, c/ Juan del Rosal, Madrid, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Segovia
authors.forename: Alicia
authors.initials: A
authors.lastname: Garcia-Falgueras
authors.forename: Beatriz
authors.initials: B
authors.lastname: Carrillo
authors.forename: Paloma
authors.initials: P
authors.lastname: Collado
authors.forename: Helena
authors.initials: H
authors.lastname: Pinos
authors.forename: Carmen
authors.initials: C
authors.lastname: Perez-Laso
authors.forename: Concepcion
authors.initials: C
authors.lastname: Vinader-Caerols
authors.forename: Carlos
authors.initials: C
authors.lastname: Beyer
authors.forename: Antonio
authors.initials: A
authors.lastname: Guillamon
mesh_terms: D000818:Animals; D002452:Cell Count; D005260:Female; D008297:Male; D009415:Nerve Net / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D009833:Olfactory Pathways / Q000166:cytology / Q000502:physiology*; D011817:Rabbits; D012727:Sex Characteristics; D018709:Statistics, Nonparametric; D019147:Vomeronasal Organ / Q000166:cytology / Q000502:physiology*