Recovery of masculine copulatory behavior from lesions of the medial preoptic area: Effects of age versus hormonal state

    loading  Checking for direct PDF access through Ovid


Two experiments tested the hypothesis that one consequence of the hormonal activation of the onset of copulation in male rats is a reduction in the plasticity of the medial preoptic area (MPOA) with respect to its role in copulation. In Exp I, 31 male rats received 1 mg of testosterone propionate daily from 10 to 45 days of age, and 30 Ss received oil injections. Ss in each of these groups received either bilateral MPOA lesions (MPOAX) or a sham operation as juveniles (28–31 days of age). The proportions of MPOAX Ss copulating as adults did not differ for Ss previously injected with oil or testosterone. In Exp II, 33 male rats were castrated at 15 days of age. These castrated Ss as well as 34 gonadally intact males received bilateral MPOA lesions or a sham operation in adulthood. Following testosterone replacement, MPOAX Ss displayed copulatory impairments regardless of hormonal state during development. Taken together, the results of these experiments suggest that the plasticity (with respect to copulation) of the neural system encompassing the MPOA is a function of some aspect of chronological age unrelated to the rat's developmental hormonal condition prior to the time of the lesion. (40 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)

    loading  Loading Related Articles