Effect of estradiol implanted in the corticomedial amygdala on the sexual behavior of castrated male rats.

ABSTRACT

1. The purpose of the present investigation was to study the effect of beta-estradiol crystals implanted in the corticomedial area of the amygdaloid body on the sexual behavior of castrated male rats. 2. The animals were divided into the following groups group I (N = 9), castrated rats; group II (N = 4), rats which had been castrated and stereotaxically implanted with cholesterol, both groups being used as controls; group III (N = 6), castrated rats with estradiol implants. Latency to the first anogenital exploration, latency to the first mount and mount frequency were determined during the pre-castration and post-castration phases and after the material had been implanted in groups II and III in 10-min observation sessions. 3. There was diminished sexual behavior of the animals in group I without spontaneous recurrence within the period observed. Group II animals, who had undergone implantation of cholesterol, an inert substance, maintained low levels of sexual behavior (post-castration 0.8 +/- 0.7 vs 0.0 +/- 0.0 and 0.5 +/- 0.5 on the 6th and 9th day after implantation, respectively). Group III animals presented a gradual increase in the number of mounts (from post-castration 1.2 +/- 0.5 to 6.5 +/- 2.7 and 4.1 +/- 1.0 on the 6th and 9th day after implantation, respectively) and a decrease of mount latency (from post-castration 431.2 +/- 55.9 to 226.1 +/- 119.6 and 51.0 +/- 28.9 on the 6th and 9th day after implantation, respectively) reaching pre-castration levels on the 6th and 9th day after beta-estradiol implantation.(ABSTRACT TRUNCATED AT 250 WORDS)