Answer:
At a level in the spinal cord
Explanation:
The gate theory was elaborated in 1965 by P.D. Wall and r. Melzack, to explain the influence of tactile skin stimulation on pain relief. It essentially admits that there exists in the medullar posterior horns (located behind the central canal of the spinal cord) a gate-acting neural mechanism that can control the passage of nerve impulses transmitted from the peripheral fibers to the CNS through the medulla.
The gate regulates the influx of nociceptive impulses even before a perception of pain is created. The variation in the passage of action potentials (nociceptive) that the gate produces is determined by the activity of the thick (A-alpha and A-beta) and thin (A-delta and C) fibers, as well as cognitive influences.
