Immobilization-induced changes in the response of striatal neurons to dexamphetamine

1. 1. Bipolar multiple unit recording electrodes were implanted in the striata of male Long-Evans rats 5-7 days prior to experimentation. 2. 2. In subsequent experiments, striatal neuronal activity in response to dexamphetamine (1.0 or 2.5 mg/kg i.p.) was recorded in either freely moving or immobilized, artificially-respired rats. 3. 3. Whereas dexamphetamine produced only excitation of striatal neurons in freely moving animals, a multiplicity of responses, ranging from excitation to inhibition, and including biphasic as well as no change responses were observed in immobilized animals. 4. 4. It is concluded that the absence of dexamphetamine-induced behavior in immobilized animals modifies the striatal neuronal response to dexamphetamine, possibly through alteration of the activity of excitatory striatal afferents.