The pattern of innervation of the corpus striatum by the substantia nigra

Radioactive proteins seen in autoradiographs of the rat striatum after injection of radioactive leucine into the substantia nigra are not evenly distributed. Areas of more intense labelling are regularly spaced in the nucleus in rows parallel to the edge of the striatum.The pattern is reminiscent of the innervation in young animals where ‘intensely fluorescent islands’ are seen. It is suggested that the areas of higher activity may correspond to the areas of dense labelling reported by others in sections of the striatum stained for acetylcholinesterase.