High resolution radioautographic investigation of [3H]GABA accumulating neurons in cat sensorimotor cortical areas.

After the injection of [3H]GABA in the cat sensorimotor cortex, radioautographic analysis of thick and thin sections showed an intense labeling of numerous nerve fibers and of some neuronal cell bodies. Labeled boutons displayed either only clear vesicles or clear and large granular vesicles. They could constitute symmetrical synaptic differentiations upon dendrites or dendritic spines. Radioactive perikarya of stellate neurons could be labeled either by direct uptake or by retrograde axonal flow.