Histochemical identification of acetylcholinesterase in dopaminergic nigrostriatal neurons

By combining histochemical procedures, evidence was obtained in the rat that acetylcholinesterase (AChE) is contained within perikarya of dopaminergic substantia nigra cells which project to the caudoputamen. Nigrostriatal neurons were identified by retrograde transport of horseradish peroxidase (HRP). Simultaneous incubation of substantia nigra sections for the presence of AChE and HRP demonstrated both reaction products in the same cell bodies. The catecholaminergic nature of these cells was determined by a loss of HRP and AChE reaction products subsequent to intranigral injection of 6-hydroxydopamine.