Ss 201j

After the baseline PWT measurement, the implanted electrodes were connected to an electrical stimulator (SEN-3301, Nihon Kohden, Tokyo, Japan) via an isolator (SS-201J, Nihon Kohden) with wire leads, allowing the animals to move freely in the cage. Monopolar electrical stimuli with a frequency of 50 Hz and pulse width of 0.2 ms were applied. The amplitude was individually determined as 70–80% of the intensity required to produce slight twitching in the lower trunk muscles or leg stretching (i.e., motor threshold), as reported in previous studies [24 (link), 48 (link)]. We defined a response as increased PWT (>130% of the initial value) on the ipsilateral side after 1-h SCS.

Electrical stimulation was applied with a stimulator (SEN-7103, isolator; SS-201J, Nihon Kohden) using rectangular current pulses (50–100 Hz, 50–100 μA, 0.2–0.3-ms pulse duration, 150–1000 train pulses). Bladder volume was maintained below the threshold for producing RMCs.

Twelve weeks after cell transplantation, electrophysiological evaluation was performed in each group. After anesthetizing with isoflurane, the distal peroneal nerve stumps of the cell transplantation sites were exposed and a bipolar stimulation electrode (UM 2-5050, Nihon Kohden, Tokyo, Japan) was placed on them. Electrical stimulation was performed with an isolator (SS-201 J, Nihon Kohden, Tokyo, Japan) connected to an electrical stimulator. The CMAP of the tibialis anterior was measured using a standard neural evoked potential recorder (MEB-9404, Neuropack S1, Nihon Kohden, Tokyo, Japan). Two stainless-steel monopolar recording electrodes (H 537 A, Nihon Kohden, Tokyo, Japan) were placed at the middle of the tibialis anterior belly and at the distal tendon. The amplitude was measured as the peak value of the waveform at the supramaximal stimulus.
Ankle joint motion was evaluated after measurement of the CMAP. Stimulation was performed using an electrical pulse (100 ms duration, 60 Hz frequency, 2.0 mA intensity, square wave) with an isolator connected to an electronic stimulator as well as CMAP. The ankle angle was calculated as the angle subtracted from the line connecting the knee and ankle and the line connecting the ankle and metatarsal head [40 (link)].