Facilitation of sexual behavior in male rats following d-amphetamine-induced behavioral sensitization

Psychopharmacology (Berl). 1999 Feb;142(2):200-8. doi: 10.1007/s002130050880.


The present study investigated the effect of sensitization, induced by repeated injections of d-amphetamine, on sexual behavior in the naive male rat tested in a drug-free state. Injections of either d-amphetamine (1.5 mg/kg, i.p.) or saline were given every other day for a total of ten injections, and this regimen induced behavioral sensitization of locomotor activity in drug-treated rats. After a 3-week post-drug period, d-amphetamine-treated rats exhibited facilitated sexual behavior, as indicated by shorter latencies to mount and intromit, and a greater percentage of rats copulating. These rats also exhibited a general increase in the amount of copulation. Furthermore, sensitized rats displayed a facilitated acquisition of sexual behavior (i.e. mount and intromission latency <300 s for 3 consecutive days). After repeated sexual experience, rats pre-treated with d-amphetamine also showed an augmented increase in level changes made in anticipation of the presentation of a receptive female. Finally, enhanced sexual behavior was independent of the environment in which repeated administration of d-amphetamine occurred, indicating that facilitation was not a consequence of conditioned associations between drug and test environment. These results demonstrate that behavioral sensitization due to repeated psychostimulant administration can "cross-sensitize" to a natural motivated behavior, such as sex. Furthermore, the subsequent facilitation of anticipatory sexual behavior (i.e. level changes) after repeated experience in rats previously treated with d-amphetamine suggests that behavioral sensitization can influence incentive learning.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Conditioning, Psychological / drug effects
  • Copulation / drug effects
  • Dextroamphetamine / pharmacology*
  • Dopamine Agents / pharmacology*
  • Female
  • Male
  • Rats
  • Rats, Long-Evans
  • Rats, Sprague-Dawley
  • Sexual Behavior / drug effects*


  • Dopamine Agents
  • Dextroamphetamine