Segmental and supraspinal actions on dorsal horn neurons responding to noxious and non-noxious skin stimuli.

摘要: Abstract 1. (1) Single dorsal horn neurons have been recorded extracellularly in 8 anesthetized (pentobarbital-Na) cats and 1 unanesthetized decerebrated cat. The animals were either spinalized by transection of the cord at L (6 experiments) or a cold block was used for reversible spinalization (3 experiments). 2. (2) Sixty-five units dorsolateral funiculus which could be excited electrical stimulation ipsilateral plantar nerves natural skin foot region. recording position microelectrode verified histologically. 3. (3) According to their excitability afferent nerve fibers receptive fields, 2 major classes distinguished Class cells myelinated axons (group II) nerves. Four out 9 low threshold cutaneous mechanoreceptors; 5 had input probably from deep receptors. , more than twice as common class cells, could, like latter, group II nerves, but addition, C-fibers. 4. (4) When stimulated naturally, virtually all received an excitatory mechanoreceptors also receptors noxious radiant heat fields. They responded heating quantitatively similar manner primary C-heat nociceptors.