Impairment of sensorimotor gating is a common feature in
schizophrenia. Rats were pretreated with either saline or the
respective compounds 10 min prior to the administration of PCP.
Prepulse inhibition (PPI) was measured 5 min after PCP treatment.
As shown in Figure 3, pretreatment with 18k (5 mg/kg, ip) or 18m
(5 mg/kg and 10 mg/kg, ip) or atypical antipsychotic risperidone
(0.5 mg/kg, ip) significantly attenuated PPI disruption induced by
PCP(5 mg/kg, ip), at least at one prepulse level. There was no signif-
icant effect of drug treatment (18k, 18m, risperidone and/or PCP)
on absolute acoustic startle responses produced by a 120 dB noise
stimulus (Fig. 3D–F), indicating that the drug treatment, at the dos-
age used in the present study, had no effect on baseline startle
reactivity. In addition, there was no significant effect on PPI when
18k was administered alone (data not shown).