Bilateral damage to the sexually dimorphic medial preoptic area/anterior hypothalamus of male ferrets causes a female-typical preference for and a hypothalamic Fos response to male body odors.
Previous studies showed that bilateral lesions of the male ferret's preoptic area/anterior hypothalamus (POA/AH), centered in the sexually dimorphic nuclei present in this region, caused subjects to seek out a same-sex male, as opposed to a female conspecific. Male subjects with POA/AH lesions (which were also castrated and given estradiol) displayed female-typical receptive behavior in response to neck gripping by a stimulus male, implying that subjects' approaches to a same-sex conspecific were sexually motivated. We asked whether the effect of POA/AH lesions on males' partner preference reflects a shift in the central processing of body odorant cues so that males come to display a female-typical preference to approach male body odorants. Sexually experienced male ferrets in which electrolytic lesions of the POA/AH caused bilateral damage to the sexually dimorphic male nucleus (MN) resembled sham-operated females by preferring to approach body odors emitted from anesthetized male as opposed to female stimulus ferrets confined in the goal boxes of a Y-maze. This lesion-induced shift in odor preference was correlated with a significant increase in the ability of soiled male bedding to induce a Fos response in the medial POA of males with bilateral damage to the MN-POA/AH. No such partner preference or neural Fos responses were seen in sham-operated males or in other groups of males with POA/AH lesions that either caused unilateral damage or no damage to the MN-POA/AH. Male-typical hypothalamic processing of conspecifics' body odorants may determine males' normal preference to seek out odors emitted by female conspecifics, leading to mating and successful reproduction.
Alekseyenko
Olga V
OV
Department of Biology, 5 Cummington St., Boston, MA 02215, USA.
Waters
Patricia
P
Zhou
Huiquan
H
Baum
Michael J
MJ
D000704:Analysis of Variance; D000818:Animals; D005260:Female; D005289:Ferrets / Q000502:physiology*; D007032:Hypothalamus, Anterior / Q000378:metabolism / Q000502:physiology*; D008297:Male; D052586:Mating Preference, Animal / Q000502:physiology*; D010675:Pheromones / Q000502:physiology; D011301:Preoptic Area / Q000378:metabolism / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D012727:Sex Characteristics; D012733:Sex Differentiation / Q000502:physiology; D012903:Smell / Q000502:physiology*
D010675:Pheromones; D016760:Proto-Oncogene Proteins c-fos