DIFFERENTIAL SEXUAL-ACTIVITY OF ISOLATED AND GROUP-HOUSED MALE-MICE -INFLUENCE OF ACUTE D-AMPHETAMINE SULFATE ADMINISTRATION

It is established that group housing can impair sexual activity of mal e mice, and that central catecholamines are involved in male sexual re sponse, but it is not known whether catecholamine mechanisms are invol ved in sexual impairment in grouped males. Injections of 0, 0.22, 0.67 , 2.0, or 6.0 mg/kg of d-amphetamine sulfate were administered 1 h bef ore testing to individually and group-housed male C57BL/6J mice. Isola ted mice showed more mounts, intromissions, and ejaculations and short er response latencies than did group-housed mice. The latencies to fir st mount, intromission, and ejaculation were nonmonotonically related to dosage, being shortest at the lowest dosage in isolated mice, but s ignificantly elevated by the higher dosages in both isolated and group ed males. The number of ejaculations was significantly elevated by mod erate dosages in both isolated and grouped mice, peaking at the 2.0 mg /kg dosage in isolated mice and at 0.67 mg/kg in grouped mice. Neverth eless, amphetamine treatment generally failed to eliminate differences between males from isolated and grouped backgrounds.