A histochemical study of GABA-transaminase in the efferents of the pallidum.

Kainic acid lesions of the globus pallidus reduce the histochemically detectable GABA-transaminase activity in the ipsilateral subthalamic nucleus. A similar decrease in enzyme activity occurs in the lateral habenula following lesions of the entopeduncular nucleus. Previous results on the localization of GABA-transaminase in efferents of the striatum indicated that such histochemistry may be a useful adjunct for the demonstration of GABA pathways. The present data are consistent with some previous literature indicating that these two pallidal efferents may contain GABA.