Activation of the sciatic nerve evoked during epidural spinal cord stimulation in rodents.

Aim: To validate the use of motor activation thresholds (MoT) to titrate stimulation amplitudes for spinal cord stimulation in rodent models.

Methods: We recorded thresholds for MoT and sciatic compound action potentials in ten Sprague-Dawley rats implanted with epidural electrodes. Strength duration curves were fitted to the threshold values.

Results: Activation thresholds were in the same order for both MoT and sciatic compound action potentials.

Conclusion: Many of the large, myelinated fibers traversing the dorsal columns in the rodent spine are activated at similar current levels to MoT. Epidural stimulation in rodents needs to be applied at amplitudes close to MoT to activate these axons.