HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 91/2/445    most recent expphysiol.2005.032193v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Barrett, G. M. Articles by Shimizu, K. Search for Related Content PubMed PubMed Citation Articles by Barrett, G. M. Articles by Shimizu, K.

¹ Kyoto University Primate Research Institute, Inuyama, Aichi, Japan² Department of Psychology, University of Richmond, Richmond, VA 23173, USA

The view that androgen action is the primary impetus underlying male-typical behaviour has been irrevocably altered by the profound perturbations in social and sexual behaviour observed in recent models of oestrogen insufficiency in male mice. Evidence is also accumulating for an involvement of oestrogens in the modulation of neural systems that are thought to play important roles in male reproductive functioning. Specifically, the serotonergic system is implicated in diverse autonomic functions, most or all of which are sensitive to oestradiol as well. Although their interaction domains have yet to be examined in male primates, roles have been established for both oestrogen and serotonin in the regulation of male sexual behaviour. We used a blinded, sham-treated and self-controlled, randomized, multitreatment cross-over design to test the hypothesis that male sexual behaviour is regulated by oestrogen modulation of the serotonergic system in intact male Japanese macaques. Regression analysis revealed that oestradiol and whole blood tryptophan, but not testosterone or 5-dihydrotestosterone, had additive, independent effects on male potentia over a range of hormone concentrations, whereas androgens were confirmed to be the primary determinants of sexual motivation. We suggest that modulation of the serotonergic system by ‘female hormones’ may be fundamental to the regulation of male mating success in higher primates. This might also explain, at least in part, why significant correlations between steroid hormones and male copulatory behaviour have traditionally proven so elusive in this order, thereby warranting a re-evaluation of the current notion that male sexual behaviour has been emancipated from activational hormonal control in higher primates.

(Received 11 September 2005; accepted after revision 13 December 2005; first published online 19 December 2005)
Corresponding author G. M. Barrett: Centre for Cancer Therapeutics, Ottawa Regional Cancer Centre, 501 Smyth Road, Ottawa, Ontario, K1H 1C4, Canada. Email: zavalabarrett{at}yahoo.com.ar