Androgen receptor immunoreactivity and mating-induced Fos expression in forebrain and midbrain structures in the male rat.
The distribution of androgen receptor immunoreactive-neurons, mapped with the PG21 anti-androgen receptor antibody, was compared in male rat brains with the distribution of Fos-immunoreactive neurons induced by mating. In gonadally intact, but not in castrated male rats, substantial numbers of androgen receptor-containing neurons were present in a variety of forebrain and midbrain regions. The PG21 antibody apparently had a higher affinity for occupied than for non-occupied androgen receptors. Androgen receptor-immunoreactive regions included the medial preoptic area and other forebrain areas previously identified as containing androgen receptors, the dorsal and ventral periaqueductal gray, and a midbrain region that included the lateral part of the central tegmental field, part of the caudal zona incerta, the subparafascicular nucleus of the thalamus and the peripeduncular nucleus. Fos-expressive neurons were essentially absent in non-mated males but were present in the brains of rats which mated to ejaculation. All brain regions in which androgen receptor-immunoreactive neurons were counted also expressed Fos immunoreactivity after mating, and there was considerable overlap between the distributions of androgen receptor- and Fos-immunoreactive neurons. In a second experiment, we used immunofluorescent techniques to document the intraneuronal co-localization of Fos with androgen receptor immunoreactivity in the medial preoptic area, medial amygdala, and central tegmental field. In these regions mating-induced Fos immunofluorescence was exclusively localized in androgen receptor-immunofluorescent neurons. However, not all androgen receptor neurons were Fos expressive, suggesting that only some androgen-sensitive neurons were activated during mating. These results are consonant with the view that hormone actions on forebrain and midbrain structures influence the neuronal activity correlated with mating.
Gréco
B
B
Department of Psychology, Emory University, Atlanta, GA 30322, USA.
Edwards
D A
DA
Michael
R P
RP
Clancy
A N
AN
D000818:Animals; D001931:Brain Mapping; D003307:Copulation / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation; D016762:Genes, fos; D008297:Male; D008636:Mesencephalon / Q000737:chemistry* / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009474:Neurons / Q000737:chemistry* / Q000502:physiology; D009830:Olfactory Bulb / Q000737:chemistry / Q000502:physiology; D009919:Orchiectomy; D016548:Prosencephalon / Q000737:chemistry* / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis* / Q000235:genetics; D051381:Rats; D011944:Receptors, Androgen / Q000032:analysis* / Q000502:physiology
D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D011944:Receptors, Androgen