Kainic acid-induced neurotoxicity in the striatum: a histofluorescent study.

Histochemical observation of catecholamine terminals in the striatum following kainic acid injections revealed a 'sphere of influence' which contained an increased intensity of dopamine fluorescence as well as non-specific tissue destruction at the injection site. The area of involvement was approximately 50% of the striatum and varied somewhat at any one dose range depending upon the site of injection. It is suggested that destruction of regulatory neuronal systems (cholinergic, GABAergic, peptidergic, etc.) results in a net increase of dopamine in the sphere of kainic acid influence.