Pharmacologic characterization of [3H]dopamine and [3H]spiperone binding in mouse cerebellum.

1. [3H]Dopamine and [3H]spiperone binding to cerebellar homogenates was characterized utilizing dopaminergic agonists, antagonists and non-dopaminergic drugs. 2. The [3H]DA binding to low affinity binding sites reveals a heterogeneous population consisting of dopaminergic as well as serotonergic and noradrenergic sites. However, the high affinity binding of [3H]DA reflects dopaminergic sites, although a small contribution of serotonergic and noradrenergic binding sites cannot be excluded. 3. [3H]Spiperone also labels a heterogeneous population of binding sites which, however, are mainly dopaminergic.