Trans-Spinal Direct Current Stimulation Alters Muscle Tone in Mice with and without Spinal Cord Injury with Spasticity

This study investigates how direct electrical current applied to the spinal cord affects muscle tone in mice, both with and without spinal cord injuries that cause spasticity. The researchers hypothesized that current flowing from the spinal cord to the sciatic nerve would reduce muscle tone, while current flowing in the opposite direction would increase it. The study used a special setup to deliver direct current stimulation (DCS) to the spinal cord and sciatic nerve of the mice. They measured nerve discharges and muscle resistance during passive muscle stretches to see how the DCS affected muscle tone. The results showed that spinal-to-sciatic DCS reduced muscle tone, while sciatic-to-spinal DCS increased it. These findings suggest that trans-spinal DCS could be a potential method for managing muscle tone abnormalities, such as hypotonia and hypertonia, in humans.

• 1
  Spinal-to-sciatic DCS reduced transit and steady stretch-induced nerve and muscle responses in both control mice and those with spinal cord injuries and spasticity.
• 2
  Sciatic-to-spinal DCS caused opposite effects, increasing nerve and muscle responses.
• 3
  DCS effects were velocity independent, suggesting that DCS has greater effects on the tonic component of the stretch reflex.