A light and electron microscopic study of GAT-1 in the monkey basal ganglia

The distribution of the GABA transporter GAT-1 was studied by immunocytochemistry and electron microscopy in the monkey basal ganglia. Dense staining was observed in the globus pallidus externa and interna, intermediate in the subthalamic nucleus, and substantia nigra, and light staining in the caudate nucleus and putamen. Staining was observed in axon terminals, but not cell bodies. Electron microscopy showed that the GAT-1 positive axon terminals formed symmetrical synapses, suggesting that they were the terminals of GABAergic neurons. Comparison of areas high in GAT-1 protein with that of GABA showed a good correlation between the density in neuropil staining for GAT-1, and that of GABA.