Dorsal caudal tail and sciatic motor nerve conduction studies in adult mice: technical aspects and normative data

Mice provide an important tool to investigate human neuromuscular disorders. The variability of electrophysiological techniques limits direct comparison between studies. The purpose of this study was to establish normative motor nerve conduction data in adult mice. The dorsal caudal tail nerve and sciatic nerve motor conduction studies were performed bilaterally on restrained anesthetized adult mice. The means and standard deviations for each electrophysiological parameter were determined in normal mice. Data were compared with inflammatory demyelinating polyneuropathy mice to determine whether these parameters discriminate between normal and abnormal peripheral nerves. Normal adult mice had a distal latency of 0.89 (+/-0.17) ms and 0.75 (+/-0.09) ms, distal compound motor unit action potential amplitude of 13.2 (+/-5.9) mV and 28.1 (+/-8.3) mV, and conduction velocity of 74.6 (+/-9.0) m/s and 76.5 (+/-8.3) m/s, respectively. These data were validated by the finding of statistically significant differences in several electrophysiological parameters that compared normal and polyneuropathy-affected mice. A standardized method for motor nerve conduction studies and associated normative data in mice should facilitate comparisons of disease severity and response to treatment between studies that use similar models. This would assist in the process of translational therapeutic drug design in neuromuscular disorders.