endplate, motorthe modification of the muscle fibre membrane at a nerve-muscle junction together with the attachment from the DENDRITE (which may consist of up to 50 boutons (SYNAPTIC KNOBS). Only one endplate occurs on each muscle fibre, approximately halfway along, and here the signal transfer from nerve to muscle takes place. ACETYLCHOLINE released from the nerve ending diffuses across this junction and depolarizes the endplate, so giving rise to an endplate potential which, as it builds up, may give rise to an ACTION POTENTIAL and initiate muscle contraction.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005