PMID- 8467350
OWN - NLM
STAT- MEDLINE
DCOM- 19930511
LR  - 20191101
VI  - 18
IP  - 1
DP  - 1993 Jan-Apr
TI  - Sexual dimorphism in the vomeronasal pathway and sex differences in reproductive 
      behaviors.
PG  - 51-74
AB  - Several years ago we hypothesized that the vomeronasal system (VNS), a complex 
      neural network involved in the control of reproductive behavior, might be 
      sexually dimorphic. This hypothesis sprung from several facts; (a) the existence 
      of steroid receptors in the VNS; (b) sexual dimorphism was already described in 
      some structures that receive vomeronasal input, such as the medial preoptic area, 
      the ventromedial hypothalamic nucleus, the ventral region of the premammillary 
      nucleus and the medial amygdaloid nucleus; and (c) the vomeronasal organ, which 
      is the receptor organ of the VNS, was also sexually dimorphic. After that point, 
      the accessory olfactory bulb (AOB), the bed nucleus of the accessory olfactory 
      tract (BAOT) and the bed nucleus of the stria terminalis were found to be 
      sexually dimorphic. The aim of the present review is to show the experimental 
      facts that confirm our earlier hypothesis and, consequently, to present the 
      existence of a sexually dimorphic multisynaptic pathway for the first time in 
      mammals. Sexual dimorphism in the VNS might provide a comprehensive approach to 
      understanding the neural bases of sexually dimorphic reproductive behavior and it 
      is suggested here that the greater number of neurons which male rats present in 
      relation to females in most VNS structures might contribute to the inhibition of 
      the expression of feminine copulatory behavior (lordosis) and maternal behavior 
      in males. In addition, the mechanisms that control the development of sexual 
      dimorphism in the VNS are discussed. The discussion takes into account the two 
      patterns of sexual dimorphism found in the rat brain. Estrogens seem to promote 
      the development of sexual dimorphism in both male and female rats. However, an 
      inhibitory role of androgens might be necessary to hypothesize when males or 
      females present a lower number of neurons and/or volume than the opposite sex. 
      There are experimental data supporting this hypothesis in the female, since 
      dihydrotestosterone seems to facilitate neuronal death in VNS structures, such as 
      the AOB and the BAOT, in which females present a lower number of neurons and 
      volume than male rats. Finally, since the lateral division of the bed nucleus of 
      the stria terminalis, which belongs to the main olfactory system (MOS), is 
      sexually dimorphic and presents anatomical relationships with some VNS structures 
      the MOS might be sexually dimorphic.
FAU - Segovia, S
AU  - Segovia S
AD  - Departamento de Psicobiologia, Universidad Nacional de Educacion a Distancia, 
      Madrid, Spain.
FAU - Guillamon, A
AU  - Guillamon A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Review
PL  - Netherlands
TA  - Brain Res Brain Res Rev
JT  - Brain research. Brain research reviews
JID - 8908638
SB  - IM
MH  - Animals
MH  - Female
MH  - Male
MH  - Nasal Septum/*innervation
MH  - Nervous System Physiological Phenomena
MH  - Neural Pathways/physiology
MH  - Nose/*innervation
MH  - *Sex Characteristics
MH  - Sexual Behavior, Animal/*physiology
RF  - 252
EDAT- 1993/01/01 00:00
MHDA- 1993/01/01 00:01
CRDT- 1993/01/01 00:00
PHST- 1993/01/01 00:00 [pubmed]
PHST- 1993/01/01 00:01 [medline]
PHST- 1993/01/01 00:00 [entrez]
AID - 0165-0173(93)90007-M [pii]
AID - 10.1016/0165-0173(93)90007-m [doi]
PST - ppublish
SO  - Brain Res Brain Res Rev. 1993 Jan-Apr;18(1):51-74. doi: 
      10.1016/0165-0173(93)90007-m.