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. 2023 May 16;10(5):ENEURO.0429-22.2023. doi: 10.1523/ENEURO.0429-22.2023

Figure 6.

Figure 6.

Dose response for the spinal and the trunk EMG recordings. A, Average evoked spinal response [ECAP, evoked synaptic activity potential ESAP (S1); upper panel] and average evoked trunk EMG (LT muscle; lower panel) response from epidural stimulation of spinal cord at varying current intensities, ranging from 200 to 1000 μA, with a train of 40 pulses (40-μs pulse width, 1 Hz) in a representative single rat. Identified waveform components of the spinal response are labeled for 1000 μA, when observable, as P1, N1, P2, N2, S1, and S2 (ESAP). ESAP (S1) becomes more distinct with increasing current intensity. A1, Dose–response curve for the ECAP (brown), ESAP (S1; pink), EMG (blue), and late-EMG (green) responses. The left axis represents the amplitude for ECAP and ESAP (S1); the right axis represents the RMS for EMG responses. Each data point represents mean ± SEM (40 trials). A2, Latencies plotted as a function of current intensities. N1 (brown), P2 (black), N2 (dark green), and S1 (ESAP, pink). Latency for the trunk EMG is defined as the latency of the first peak in the EMG response. Data represented as mean ± SEM (40 trials). B, Same as A, but only at two SCS current intensities: 400 and 1000 μA, prelidocaine and 20 min after lidocaine in the same rat. ECAP- Evoked Compound Action Potential; ESAP - Evoked Synaptic Activity Potential; P1, N1, P2 - ECAP waveforms; S1- ESAP waveform.Figure Contributions: Mahima Sharma performed the experiments and analyzed the data.