Combined visualization of central catecholamine- and acetylcholinesterase-containing neurons: application of the glyoxylic acid and thiocholine histochemical methods to the same Vibratome section.

This paper describes a procedure for demonstration of catecholamine- and acetylcholinesterase-containing neurons in the same section of central nervous tissue. The brains are first processed according to the glyoxylic acid (GA) fluorescence method for catecholamine neurons, i.e. perfused with an ice-cold GA solution, sectioned on a Vibratome instrument, immersed in a GA solution and dried under a stream of warm air. The unmounted sections are examined and photographed in the fluorescence microscope, and then stained for acetylcholinesterse according to Holmstedt's modification of the Koelle thiocholine method (incubation for 4-6 h with acetylthiocholine as substrate and Mipafox as inhibitor of non-specific cholinesterases). the sections are then examined in the light microscope, rephotographed, and the picture compared with that following the GA reaction. The present technique makes possible, for the first time, detailed light microscopical studies of themorphological relations between central catecholamine-and acetylcholinesterase-containing neurons in the same section.