Aspects Of Male Sexual Behavior Research Articles

Food conditioning, castration, testosterone administration and sexual behavior in the male rat

Chronically food-deprived male rats, when paired with a female rat in heat, were rewarded by receiving a food pellet following each intromission. Following castration there was a rapid decline in all aspects of male sexual behavior: after 3 weeks all sex behavior had stopped. There were no differences between the conditioned males and their yoked controls. Substitution with two doses of testosterone (through silastic implants) restored sexual behavior, but equally so in the conditioned and the control animals. Removal of the testosterone implant again caused a very rapid decline in sexual behavior, no differences between experimental and yoked control males. These results suggest that food, as a non-sexual stimulus, does not cause hungry male rats to continue to copulate for prolonged periods following castration. Furthermore, the combination of chronic food deprivation plus castration do summate with each other in the very rapid decline and cessation of male sexual performance.

Sexual behavior of the male schizophrenic: the impact of illness and medications.

The literature concerning the impact of (a) the schizophrenic illness and (b) the neuroleptic drugs (which are the most commonly employed medications for this disorder) on male sexual behavior is critically reviewed in the light of what is currently known about the interaction of both the schizophrenic illness and the neuroleptic drugs with hormones and neurotransmitters known to play a role in male sexual behavior. The effect of the schizophrenic illness on male sexual behavior is unclear, but there are some indications that chronic, severe schizophrenia may exert detrimental effects on many aspects of male sexual behavior. As for neuroleptic drugs, a wealth of evidence suggests that they have many detrimental effects on male sexual behavior. Nevertheless, since the introduction of these drugs, the reproductive rates of male schizophrenics have increased. The multiplicity of factors involved in the sexual behavior of the schizophrenic patient is emphasized. It is concluded that the sexual behavior of the male schizophrenic provides an important forum for studying the interaction between psychological, sociological and biochemical-pharmacological factors which determine sexual behavior.

Activation and differentiation of sexual behavior and translocation of hypothalamic estrogen receptors in rats by 6α-fluorotestosterone

Androgens classified as nonaromatizable in placental assay systems typically do not mimic testosterone's effects on sexual behavior in rats. 6α-Fluorotestosterone is an exception. To pursue this challenge to the aromatization hypothesis, we compared several behavioral and neuroendocrine effects of 6α-fluorotestosterone propionate (6α-fluoro-TP) with those of testosterone propionate (TP). Even at a very low dose (6.25 μg/100 g/day), 6α-fluoro-TP maintained most aspects of male sexual behavior as well as TP. It was slightly less potent than TP for inhibiting gonadotropin secretion (testicular development) in prepubertal males. Given neonatally, these androgens were equally likely to induce anovulatory sterility. 6α-Fluoro-TP defeminized sexual development in females and neonatally castrated males half as effectively as TP based on lordosis:mount ratios following estrogen and progesterone therapy in adulthood. Neither androgen masculinized sexual behavior. The behavioral effects of 6α-fluoro-TP correspond to its ability to inhibit cell nuclear accumulation of 17β-[ 3H]estradiol in the hypothalamuspreoptic area. When injected on a schedule like that used to activate male sexual behavior, the two androgens reduced estrogen uptake equally. When injected into adult castrates on a schedule like that used to defeminize sexual development, 6α-fluoro-TP blocked estrogen uptake half as well as TP. 6α-Fluorotestosterone did not alter estrogen uptake when injected simultaneously with 17β-[ 3H]estradiol. These data suggest that 6α-fluorotestosterone activates male behavior and defeminizes development because it translocates estrogen receptors in the brain, probably via an aromatized metabolite. Hence androgen aromatizability in the placenta may not reflect neural metabolism and cannot predict the behavioral or neuroendocrine effects of androgens.

Sexual motivation and medial preoptic self-stimulation in male rats

Self-stimulation and sexual behavior of male rats with electrodes implanted in the medial preoptic area were studied in an experiment in which the animals were castrated and subsequently treated with testosterone propionate. The rewarding effect of an electrical stimulus in this area proved to depend upon the presense of testosterone. The results of this study provide additional evidence for the importance of the medial preoptic area in the motivational aspects of male sexual behavior.