Strain differences in the isolation-induced effects on prepulse inhibitionof the acoustic startle response and on locomotor activity

The authors investigated the effects of isolation rearing on acoustic start le response, prepulse inhibition (PPI), its modification by apomorphine, an d locomotor activity in 3 rat strains: Wistar (WS), Sprague-Dawley (SD), an d Lister hooded (LH). SD and LH, but not WS. showed isolation-induced PPI d eficits. In 2 consecutive PPI tests, only SD isolates showed significant PP I deficits. An isolation rearing effect in LH was significant only. in the Ibt PPI test. Apomorphine dose-dependently (0.0-0.5 mg/kg) disrupted PPI. b ut sensitivity to the drug differed, with WS and SD rats being more sensiti ve to lower doses (0.01-0.05 mg/kg) than LH rats (0.5 mg/kg). Isolates, irr espective of strain, did not differ from grouped rats in their response to the apomorphine challenge. Only WS and LH isolates demonstrated significant ly increased locomotor activity. Strain differences in the different parame ters measured did not predict isolation-induced effects on PPI.