Inhibition of nociceptive evoked activity in spinal neurons through a dorsal column-brainstem-spinal loop.

In decerebrate-decerebellate cats, dorsal column stimulation (DCst), rostral to bilateral dorsal column cuts, inhibited dorsal horn neurons discharging to various types of nociceptive stimuli. Similar inhibitory effects were observed from conditioning nucleus raphe magnus stimulation. Activation of this dorsal column-brainstem-spinal loop could be part of an important supraspinal "gating' system to account for the alleviation of pain both by DCst and peripheral nerve stimulation in man.