Ri. Wood et Sw. Newman, INTEGRATION OF CHEMOSENSORY AND HORMONAL CUES IS ESSENTIAL FOR MATINGIN THE MALE SYRIAN-HAMSTER, The Journal of neuroscience, 15(11), 1995, pp. 7261-7269
Mating behavior in the male hamster is dependent upon both chemosensor
y and hormonal cues, and copulation is abolished if either signal is i
nterrupted, Through reciprocal interactions of these signals, chemosen
sory stimuli increase circulating testosterone in the male, and the ma
le's hormonal status influences his attraction to female pheromones, F
urthermore, anatomical data suggest that these signals are transmitted
through parallel pathways in separate subdivisions of the medial amyg
daloid nucleus, bed nucleus of the stria terminalis (BNST) and medial
preoptic area (MPOA), The aim of this study was to determine if the in
tegration of chemosensory and hormonal cues is essential for mating, W
e combined an intracerebral implant of testosterone in BNST/MPOA with
removal of a single olfactory bulb (UBx), ipsilateral or contralateral
to the steroid implant, Previous studies have demonstrated that testo
sterone implants which stimulate androgen receptor-containing neurons
in posteromedial BNST and MPOA can increase mounting in males castrate
d for 12 weeks, Moreover, unilateral bulbectomy alone does not prevent
mating, In the present study, ipsilateral UBx prevents communication
between hormonal and chemosensory circuits, Sexually experienced males
were used. Twelve weeks after castration, a single olfactory bulb was
removed, and each male received a testosterone-filled cannula (23 ga)
directed at the MPOA, Two weeks later, sexual activity increased in s
ix males with implants in BNST/MPOA and contralateral UBx, but copulat
ion was not restored in eight males with ipsilateral UBx despite equiv
alent implant placement, This study demonstrates that communication be
tween neurons receiving hormonal signals and chemosensory cues is requ
ired for mating behavior.