The neuromuscular junction (NMJ) forms a chemical bridge between the motor neurone and skeletal muscle. The final short section of the motor nerve is unmyelinated and comes to lie in a gutter on the surface of the muscle fibre at its mid-point – each being innervated by a single axonal terminal from a fast Aα neurone (en plaque appearance). However, for the intra-ocular, intrinsic laryngeal and some facial muscles the pattern of innervation is different with multiple terminals from slower Aγ neurones scattered over the muscle surface (en grappe appearance).