The Innervation of the Mesothoracic Flexor Tibiae Muscle of the Locust

The anatomy and innervation of the mesothoracic flexor tibiae muscle indicated a subdivision into proximal, middle and distal flexors. The muscle is innervated by 12 excitors, two inhibitors and two dorsal unpaired median (DUM) neurones. The motor axons were identified by (a) the height of the action potentials recorded extracellularly from the flexor nerve branches of an intact locust, (b) the EPSPs or IPSPs and the tension which they produced in the muscle when they were stimulated and (c) the distribution on the muscle. There was some independent innervation of proximal, middle and distal flexors.