The neurosteroid Allopregnanolone decrease receptivity and anxiety behavior in female rats

ESCUDERO C.; GIULIANI F.; BAZZOCCHINI V.; GARC¨ªA S.; LACONI M.; YUNES R.; CABRERA R.

San Luis

Congreso; XXVII Reuni¨®n Cient¨ªfica Anual de la Sociedad de Biolog¨ªa de Cuyo; 2009

The neurosteroid Allopregnanolone decrease receptivity and anxiety behavior in female rats. Escudero C, Giuliani F, Bazzocchini V, Garcia S, Laconi M, Yunes R, Cabrera R. Instituto de Investigaciones Biom¨¦dicas-FCS-UM. IMBECU-CONICET. rcabrera@fcm.uncu.edu.ar Gonadal and adrenal steroids heavily impact sexual function in the brain. The nervous system synthesizes steroids de novo from cholesterol, called neurosteroids. The 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 behavioural changes, ovariectomized (OVX) rats (8-10/group) were primed with estrogen (E) and progesterone (P) and infused 48 hrs later with vehicle (saline) or Allo (6¦ÌM) to the lateral ventricule. Rats were assessed in a battery of exploratory (open field), anxiety (elevated plus maze), and sexual (paced mating) tasks. Results were expressed as the media ¡À SEM and statistically analyzed by t-test, p<0.05 was considered significant. Allo administration significantly decrease lordosis quotients compared to vehicle administration (10¡À2.6% vs. 78.5¡À6.3%, p<0,001), but not modifies exploratory behavior. EP-primed females infused with Allo show less anxiety (elevated time spent on the open arms) than vehicle group ((83.2¡À22.9 secs vs. 6.8¡À3.2 secs, p<0,005). The results support the hypothesis that Allo is a potent modulator of anxiety and reproductive behaviours. The contemporaneous changes in anxiolytic and sexual behaviours as response of Allo administration might be functionally linked to reproductive processes in female rats.