Kainic acid lesions dissociate [3H] spiperone and [3H]cis-flupenthixol binding sites in rat striatum

The effects of striatal kainic acid lesions on [3H] cis-flupenthixol ([3H]FPT) and [3H]spiperone (3H-SPIP) binding to dopamine (DA) receptors in control and lesioned striata were examined. Significant reductions in both binding parameters were observed, [3H] FPT binding was depleted to a greater extent than [3H] SPIP binding. Reductions in both [3H] FPT and [3H] SPIP binding were significantly correlated with reductions in glutamic acid decarboxylase activity. After complete loss of GAD activity, 30-40% of [3H] SPIP binding sites remained in the lesioned striata, whereas all [3H] FPT binding sites were destroyed. The results are discussed in relation to the presence of distinct types of DA receptors in rat striatum, and ligand binding to these receptors.