Motor axon excitability during Wallerian degeneration.

摘要: Axonal loss and degeneration are major factors in determining long-term outcome patients with peripheral nerve disorders or injury. Following of axonal continuity, the isolated stump distal to lesion undergoes Wallerian several phases. In initial 'latent' phase, action potential propagation structural integrity segment maintained. The aim this study was investigate vivo changes membrane function motor axons during phase degeneration. Multiple indices excitability tibial at ankle axotomy were monitored by 'threshold-tracking'. plantar compound muscle potentials (CMAPs) recorded under anesthesia three animal models: 8-week-old wild-type mice, slow mutant mice 3-year-old cats. We found that progressive decrease CMAP following crush injury associated slowing conduction marked abnormalities excitability: increased peak threshold deviations both depolarizing hyperpolarizing electrotonus, enhanced superexcitability recovery cycle rheobase. context decreased current-threshold slope chronaxie, these consistent a voltage-dependent Na(+) K(+) conductances. Our data suggest 'latent phase' there is gradual disruption ion-channel leading precede failure disintegration. These findings may have clinical relevance should be taken into consideration interpretation specificity measures characterized