EFFECTS OF A CONTUSIVE SPINAL CORD INJURY ON CORTICALLY-EVOKED SPINAL SPIKING ACTIVITY IN RATS

This study investigates how spinal cord injuries (SCI) affect the communication between the brain and spinal cord in rats, specifically focusing on hindlimb movement. The researchers used electrical stimulation of the motor cortex (the brain area controlling movement) and recorded the resulting activity in the spinal cord to understand changes in neural signaling after SCI. The findings suggest that after SCI, alternative pathways, particularly the cortico-reticulospinal tract, may play a crucial role in transmitting signals from the brain to the spinal cord, potentially compensating for damage to the primary corticospinal tract.

• 1
  In healthy rats, electrical stimulation of the motor cortex evoked reliable spike activity in the spinal cord at short latencies (10-12 ms) and longer latencies (20-60 ms).
• 2
  In SCI rats, short-latency responses were retained, while long-latency responses and EMG responses were disrupted or eliminated.
• 3
  The retention of short-latency responses in SCI rats suggests that spared descending spinal fibers, most likely via the cortico-reticulospinal pathway, can still depolarize spinal cord neurons after injury.