Microinjection of the dopamine antagonist cis-flupenthixol into the MPOA impairs copulation, penile reflexes and sexual motivation in male rats.
Microinjection of the dopamine antagonist cis-flupenthixol into the medial preoptic area was previously shown to impair male rat copulatory behavior. The present experiments provide further evidence of cis-flupenthixol's inhibitory effects on male sexual behavior. Following microinjections of moderate to high doses of cis-flupenthixol, males exhibited slower copulatory rates and fewer ejaculations in copula, fewer ex copula erections and penile movements, and reduced sexual motivation in an X-maze. Locomotion in the X-maze was not significantly affected. Microinjections of the inactive isomer trans-flupenthixol produced no change in any behavioral measure, indicating that cis-flupenthixol's effects were receptor mediated. We suggest that dopamine receptors in the MPOA influence copulation primarily by regulating reflexive and motivational factors, but not locomotion.
Warner
R K
RK
Department of Psychology, State University of New York at Buffalo, Amherst 14260.
Thompson
J T
JT
Markowski
V P
VP
Loucks
J A
JA
Bazzett
T J
TJ
Eaton
R C
RC
Hull
E M
EM
D000818:Animals; D003307:Copulation / Q000187:drug effects*; D005260:Female; D005475:Flupenthixol / Q000008:administration & dosage / Q000494:pharmacology*; D007858:Learning; D008297:Male; D008845:Microinjections; D009042:Motivation; D010413:Penis / Q000187:drug effects / Q000502:physiology*; D011301:Preoptic Area / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D012016:Reference Values; D012018:Reflex / Q000187:drug effects; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D005475:Flupenthixol