B. Planas et al., ACTIVATION OF GALANIN PATHWAYS ACROSS PUBERTY IN THE MALE-RAT - GALANIN GENE-EXPRESSION IN THE BED NUCLEUS OF THE STRIA TERMINALIS AND MEDIAL AMYGDALA, Neuroscience, 63(3), 1994, pp. 851-858
Galanin and vasopressin are coexpressed in the bed nucleus of the stri
a terminalis and medial amygdala of the male rat. In adult males, the
level of gene expression for both peptides in these regions is depende
nt on circulating levels of testosterone. We hypothesized that galanin
messenger RNA levels would be enhanced in adult males compared with p
repubertal males due to the rise in plasma testosterone levels. We use
d in situ hybridization and quantitative autoradiography to measure ga
lanin messenger RNA in cells of the bed nucleus of the stria terminlis
and medial amygdala of prepubertal and adult male rats. Our results s
how that significantly (P less than or equal to 0.05) more galanin mes
senger RNA expressing neurons are detectable in the bed nucleus of the
stria terminalis of adult compared with prepubertal male rats. In con
trast, no differences were observed between the groups in the number o
f labeled neurons detected within the medial amygdala. However, the av
erage labeling intensity was significantly enhanced in both the bed nu
cleus of the stria terminalis (P less than or equal to 0.001) and medi
al amygdala (P less than or equal to 0.001) of adult compared with pre
pubertal animals. The present findings are consistent with the hypothe
sis that gonadal hormones regulate galanin gene expression in some bra
in regions and suggest that the activation of the hypothalamic-pituita
ry-gonadal axis which occurs naturally with puberty is associated with
activation of galanin pathways in the bed nucleus of the stria termin
alis and medial amygdala.