Facilitation of sexual behavior and enhanced dopamine efflux in the nucleus accumbens of male rats after D-amphetamine-induced behavioral sensitization.
Level 5 - mechanism / opinion, no new human data
Animal research (bench/rodent microdialysis study)
PubMed 9870973 · doi:10.1523/JNEUROSCI.19-01-00456.1999
What was done
Male rats received 10 intermittent injections of either D-amphetamine (1.5 mg/kg, i.p.) or saline administered every other day. After a three-week drug-free withdrawal period, animals underwent testing for sexual behavior combined with microdialysis measuring dopamine efflux in the nucleus accumbens during an anticipatory phase (receptive female behind a screen) and during active copulation.
What was found
In the presence of a receptive female behind a screen, D-amphetamine-sensitized rats exhibited higher nucleus accumbens dopamine efflux than saline controls (35% vs 17%). When the screen was removed, sensitized rats showed significantly shorter mount latency and an overall increase in copulatory behavior. During the first 10 minutes of copulation, sensitized rats had a greater increase in dopamine efflux from baseline compared to controls (60% vs 37%).
Why it matters
This paper demonstrates that psychostimulant sensitization cross-sensitizes to natural motivated behaviors, with enhanced mesolimbic dopamine release accompanying both appetitive and consummatory sexual responses.
Limits
The study was conducted entirely in male rats, limiting direct generalizability to humans and female subjects. The abstract does not report sample sizes, specific p-values, or confidence intervals, and only a single dose regimen and withdrawal time point were tested.
Cited by
- partial In mice, sex increases dopamine release by 100%, whereas amphetamines increase dopamine release by 1,000%.