| Abstract: | Ibotenic acid lesions of the caudate-putamen in rat brain resulted in dramatic reductions in 3H]SCH 23390 binding in both the ipsilateral caudate-putamen and substantia nigra reticulata as assessed by quantitative autoradiography. Nigral ibotenic acid and 6-hydroxydopamine lesions did not significantly alter the binding in either structure. This indicates that D1 receptors in the caudate-putamen are postsynaptic on striatal neurons, while those in the substantia nigra reticulata are presynaptic on nerve terminals originating in the caudate-putamen. |
