Lack of spontaneous activity of cutaneous spinal dorsal horn neurons in awake, drug-free, spinally transected cats.

Extracellular single-unit activity was recorded from neurons with cutaneous input in the dorsal horn of the spinal cord (L4-L6) of awake, drug-free cats before (for several weeks) and after (day 1 through day 7) cord transection (T12). The spontaneous activity of the neurons was minimal or nonexistent in both recording conditions. The lack of spontaneous activity following spinal cord transection contrasts sharply with activity recorded in acute spinal-cord transected preparations in which high rates of spontaneous activity have been reported. This discrepancy may reflect an important difference between the chronic, awake, drug-free and acute preparations.