S. Rivasarancibia et F. Vazquezpereyra, HORMONAL MODULATION OF EXTINCTION RESPONSES INDUCED BY SEXUAL STEROID-HORMONES IN RATS, Life sciences, 54(21), 1994, pp. 363-367
Citations number
20
Categorie Soggetti
Biology,"Medicine, Research & Experimental","Pharmacology & Pharmacy
A functional interrelation between the nervous and endocrine systems h
as been established. However, few studies have dealt with the effects
of sexual steroids on learning and memory. The aim of this work was to
determine whether sexual steroid hormones could modulate the extincti
on response of a passive avoidance conditioning in rats. Male Wistar r
ats, randomly assigned to five groups, two controls and three experime
ntal groups, were submitted to a one-trial passive avoidance condition
ing and tested for their retention 24 hr after and during 10 weeks. On
e control group received no treatment at all, the other received veget
able oil, and the three experimental received 20 mg of testosterone en
anthate, 0.8 mg estradiol valerate, or 4 mg nandrolone decanoate, resp
ectively. All substances were applied in a 0.3 ml volume, 24 hours bef
ore training and before testing for retention each week during 10 week
s. Results indicate that the extinction process is modulated by these
hormones, since testosterone and estradiol facilitate extinction, wher
eas the anabolic androgen produced a resistance to the extinction proc
ess.