Dopamine D2 receptors in substantia nigra in schizophrenia

Dopamine D2 receptors were assessed in samples of substantia nigra from controls and schizophrenics. Specific [3H]spiperone binding was significantly increased in both neuroleptic-free and neuroleptic-treated schizophrenics. This supports our previous suggestion that the increase in D2 receptors observed in striatum of schizophrenics is not wholly due to neuroleptic medication.