Effects of risperidone, an atypical antipsychotic drug, on excitatory synaptic responses in the perforant path-dentate gyrus pathway in chronically prepared rabbits.

The effects of an atypical antipsychotic drug, risperidone, were examined on excitatory synaptic responses in the dentate gyrus by single electrical stimulations to the perforant path and the induction of long-term potentiation (LTP) in this pathway in chronically prepared rabbits. Any of 0.5, 1.0 and 2.0 mg/kg doses of risperidone intraperitoneally injected had virtually no effect on the excitatory synaptic responses. However, these three doses of risperidone dose-dependently suppressed the LTP induction.