A horseradish peroxidase method for the identification of the efferents of acetyl cholinesterase-containing neurons.

Abstract

This method has higher stability and better tinctorial contrast. Since it permits the simultaneous visualization of acetylcholinesterase (AChE) and horseradish peroxidase (HRP) in the same tissue section, the efferent projections of AChE-rich perikarya may be determined without ambiguity following intracerebral injections of HRP. This method has enabled a preliminary analysis of efferents from the rhesus monkey basal forebrain to neocortex, to the hippocampus and to the olfactory bulb, in terms of both topographical distribution and histochemical specificity. Although the ability to investigate a histochemically distinct group of neurons is inherently of considerable interest, the implication of these AChE-rich cells in central cholinergic transmission may introduce additional significance to their connections.