CASTRATION, GONADAL-HORMONES AND SIDMAN AVOIDANCE ACQUISITION

The effects of hormones on the acquisition of a leverpress Sidman avoidance task were investigated. Rats were assigned to six groups: (a) castration with estradiol treatment; (b) castration with estradiol plus progesterone treatment; (c) castration with progesterone treatment; (d) castration with testosterone treatment; (e) castration with saline treatment; (f) sham castration with saline treatment. Shocks, responses and interresponse times were recorded during a two-hour acquisition session. Following acquisition, blood was drawn and serum hormone levels were determined by radioimmunoassay. Consistent with previous reports, estradiol-treated rats showed a nonsignificant trend toward superior acquisition of the task. Estradiol, relative to sham treatment, produced a significant reduction in individual variation in the acquisition of the avoidance task. © 1979.