Kainic acid lesions decrease striatal dopamine receptors and 1,4-dihydropyridine sites

The effects of intrastriatal injection of kainic acid (2 μl, 1 mg/ml) in the rat were determined. Four weeks after the lesioning, striatal dopamine receptors and 1,4-dihydropyridine sites were measured by radioligand binding with [³H]spiperone and [³H]nimodipine, respectively. Dopamine receptor and 1,4-dihydropyridine binding densities were decreased by 58% and 43% respectively, with no change in binding affinity for either ligand. 1,4-Dihydropyridine-sensitive Ca²⁺ channels may be located primarily on postsynaptic elements.