Suppression of activity in spinal nocireceptive 'low back' neurons by paravertebral somatic stimuli in the cat

Single-unit recording techniques were used to investigate spinal cord neurons likely to be involved in low back pain. Most dorsal horn neurons with somatic receptive fields in the low back region have complex receptive fields involving deep and superficial tissues. This report shows, for the first time, that activity in some nocireceptive 'low back' neurons is suppressed by somatic stimulation of discrete sites within the larger excitatory receptive field. Both weak and intense mechanical stimulation of skin or deep tissues suppressed activity in some neurons. The neurons in this population tested for rostral projections had long ascending axons.