Postpubertal social isolation and male sexual behavior in rodents: Facilitation or inhibition is species dependent

Experiment 1 examined male Swiss-Webster, C57, and DBA mice that were housed individually or grouped for 2 weeks and subsequently presented with ovariectomized, estrogenprimed, progesterone-treated females, Within each strain, social isolates showed more mounts, intromissions, and ejaculations and shorter latencies to first mount and intromission, Experiment 2 involved a similar comparison of isolated and grouped male rats, hamsters, and gerbils, Isolation produced no major effect in hamsters but reduced performance in rats and gerbils, The results suggest that facilitation of sexual action patterns by isolation is characteristic of the mouse species, Response decrements with postpubertal isolation in the rat resemble effects of prepubertal isolation in this species, These species differences may parallel differences in physiology and social behavior.