VLDLR mice on postnatal day 120 were randomly assigned to treatment with vehicle, 10 mg/kg, 15 mg/kg, or 20 mg/kg of the NMDA-receptor antagonist phencyclidine (PCP). All mice received all doses, in counterbalanced order. Animals were tested for prepulse inhibition to an acoustic startle stimulus. Test sessions consisted of individual trials that presented prepulse acoustic stimuli 2, 4 and 8 dB above 65 dB background noise (i.e., 67, 69 and 73 dB). Values represent group means (± SEM). Startle magnitudes (arbitrary units) at each dose are inset in graph. * indicates significantly different compared to wildtype mice, p < 0.05. WT = Wildtype (n = 19); HT = Heterozygote (n = 26); KO = Homozygous knockout (n = 27).