Fig. 5.

Mean current (mA) required to generate evoked compound action potential thresholds (ECAPT) and motor thresholds (MT) in freely behaving sham SCS-ON (A, C) and SNI SCS-ON (B, D) animals using 2 Hz 200 µs and 50 Hz 200 µs. A ECAPT in sham SCS-ON animals was 0.038 ± 0.006 mA and MT was 0.082 ± 0.010 mA using 2 Hz 200 µs. B ECAPT in SNI SCS-ON animals was 0.026 ± 0.004 mA and MT was 0.065 ± 0.012 mA using 2 Hz 200 µs. C ECAPT in sham SCS-ON animals was 0.038 ± 0.006 mA and MT was 0.084 ± 0.007 mA using 50 Hz 200 µs. D ECAPT in SNI SCS-ON animals was 0.026 ± 0.003 mA and MT was 0.064 ± 0.006 mA using 50 Hz 200 µs. Using both stimulation conditions, the current required to elicit MT was significantly higher than the current required to generate ECAPT in both sham SCS-ON (2 Hz 200 µs: p < 0.001; 50 Hz 200 µs: p < 0.001) and SNI SCS-ON (2 Hz 200 µs: p = 0.043; 50 Hz 200 µs: p < 0.001) animals. Stimulation was applied at the T13 vertebral level and recordings were measured antidromically to the stimulation channel. Data are presented as mean ± SEM, n = 6. p < 0.05 (corrected) was used as the significance level (paired t-test). * denotes significance compared to MT. SNI: spared nerve injury