The neurosteroid allopregnanolone decreases receptivity and anxiety behavior in female rats

ESCUDERO C; GIULIANI F; BAZZOCCHINI V; GARCÍA S; LACONI M; YUNES R; CABRERA R

SAN LUIS

Conferencia; XXVII REUNIÓN CIENTÍFICA ANUAL DE LA SOCIEDAD DE BIOLOGÍA DE CUYO; 2009

SOCIEDAD DE BIOLOGIA DE CUYO

Gonadal and adrenal steroids heavily impact sexual function in the brain. The nervous system synthesizes steroids de novo from cholesterol, called neurosteroids. Allopregnanolone (Allo) levels change also with behavioral and/or environmental stimuli and may have a role in other reproductively-relevant behaviors, such as exploration and anxiety (socio-sexual behaviours).To investigate these behavioral changes, ovariectomized (OVX) rats (8-10 per group) were primed with estrogen (E) and progesterone (P) and infused 48 h later with vehicle (saline) or Allo (6 ƒÊM) in the lateral ventricle. Rats were assessed in a battery of exploratory (open field), anxiety (elevated plus maze), and sexual (paced mating) tasks. Results were expressed as mean ± SEM and statistically analyzed by a Student t-test; p<0.05 was considered significant. Allo administration significantly decreased lordosis quotients compared to vehicle administration (10±2.6% vs. 78.5±6.3%, p<0.001), but did not modify exploratory behavior. EP-primed females infused with Allo showed less anxiety (elevated time spent on the open arms) than vehicle group ((83.2±22.9 secs vs. 6.8±3.2 secs, p<0,005). The results support the hypothesis that Allo is a potent modulator of anxiety and reproductive behaviors. The contemporaneous changes in anxiolytic and sexual behaviors in response of Allo administration might be functionally linked to reproductive processes in female rats. significant. Allo administration significantly decreased lordosis quotients compared to vehicle administration (10±2.6% vs. 78.5±6.3%, p<0.001), but did not modify exploratory behavior. EP-primed females infused with Allo showed less anxiety (elevated time spent on the open arms) than vehicle group ((83.2±22.9 secs vs. 6.8±3.2 secs, p<0,005). The results support the hypothesis that Allo is a potent modulator of anxiety and reproductive behaviors. The contemporaneous changes in anxiolytic and sexual behaviors in response of Allo administration might be functionally linked to reproductive processes in female rats. t-test; p<0.05 was considered significant. Allo administration significantly decreased lordosis quotients compared to vehicle administration (10±2.6% vs. 78.5±6.3%, p<0.001), but did not modify exploratory behavior. EP-primed females infused with Allo showed less anxiety (elevated time spent on the open arms) than vehicle group ((83.2±22.9 secs vs. 6.8±3.2 secs, p<0,005). The results support the hypothesis that Allo is a potent modulator of anxiety and reproductive behaviors. The contemporaneous changes in anxiolytic and sexual behaviors in response of Allo administration might be functionally linked to reproductive processes in female rats.