AMPH effects on PPI in rats whose vehicle PPI levels were either below (“low gating”) or above (“high gating”) the median levels for that strain. A. Rats from Experiment 2a, that received ic infusions into the NACc (pooled from medial and lateral infusion sites). # significant main effect of strain (LE<SD) after ic vehicle infusion. * significant reduction in PPI compared to vehicle dose (for 20 and 40 μg doses in SD “low gating”, and in all active doses of SD and LE “high gating”). B. Same comparisons as in A, except with rats in Experiment 1, that received sc injection of AMPH into the nape of the neck. * significant reduction in PPI compared to vehicle dose (for 3.0 and 4.5 mg/kg doses in SD “low gating”, and in all active doses of SD (but not LE) “high gating”).