Demonstration of acetylcholinesterase by semipermeable membrane technique: estimation of soluble and fixation-labile portions in different regions of the central nervous system.

A histochemical method for the demonstration of acetylcholinesterase using semipermeable membranes is described. This technique prevents any loss of enzyme activity caused by dissolution and/or fixation. The soluble and fixation-labile portions of acetylcholinesterase were estimated in several regions of the central nervous system of the rat and differences were found. The method improves the accuracy of the histochemical demonstration of the acetylcholinesterase on the light microscopical level.