Evaluation of gastrocnemius motor evoked potentials induced by trans-spinal magnetic stimulation following tibial nerve crush in rats

Peripheral nerve injuries induce long-lasting physiological and severe functional impairment due to motor, sensory, autonomic denervation. Preclinical models allow us study the process of damage, evaluate capacity peripheral nervous system for spontaneous recovery, test diagnostic tools assess damage subsequent recovery. Methods: In this on Sprague-Dawley rats, we: 1) compared use two different anesthetics (isoflurane urethane) evaluation motor evoked potentials (MEPs) induced by trans-spinal magnetic stimulation (TSMS) in gastrocnemius brachioradialis muscles; 2) monitored evolution MEPs applying paired-pulse neuromuscular junction activity; 3) evaluated MEP amplitude before after left tibialis crush (up 7 days post-injury under isoflurane anesthesia). The results showed that muscle had higher amplitudes anesthesia as with urethane demonstrating motoneuronal excitability TSMS. Following tibial crush, a significant reduction was observed injured side, mainly axonal from initial crush. No recovery muscles up post-crush; even section did not any variation residual amplitude, suggesting effectively severed fibers. These observations were confirmed histologically drastic remaining myelinated fibers crushed nerve. data demonstrate TSMS can be reliably used noninvasively function rats. This method could therefore readily applied conductance clinical environment. research funded Chancellerie des Universités de Paris (Legs Poix) (SV, MB), Fondation France (SV), Médisite INSERM (MB, SV, AM), Université Versailles Saint-Quentin-en-Yvelines AM) Ministry Science Technology 109-2636-B-110-001 (KZL). is full abstract presented at American Physiology Summit 2023 meeting only available HTML format. There are no additional versions or content abstract. involved peer review process.