FASCICULINS, ENZYME SITE-DIRECTED POLYPEPTIDES, AS MOTOR-NEURON RESEARCH TOOLS

In order to examine the ability of motor neurones to take up fasciculi n (FAS) and transport it centrally from muscle terminals to the spinal cord, we injected purl FAS 2, a powerful acetylcholinesterase (AChE) inhibitor, into mouse gastrocnemius muscle. 21 h later, histochemistry and biochemistry of spinal cord AChE showed an almost complete inhibi tion of motoneuronal AChE, limited to the spinal cord segmental levels corresponding to the injected muscle. Axon transport of FAS can be ex ploited to direct peripherally-injected FAS to neurones located in the central nervous system (CNS).