Electrophysiological Evidence Of The Convergence Of Somatic And Visceral Afferents Onto The Neurons In The Sacral Dorsal Commissural Nucleus And Their Relationship With Nitric Oxide Synthase Positive Structures

The present paper is divided into three parts.I. VISCERAL AND SOMATIC PRIMARY AFFERENT INPUTS CONVERGE NCE ONTO THE NEURONS OF THE SACRAL DORSAL COMMISSURAL NUCLEUS IN THE CATResponses of neurons in the cat sacral dorsal commissural nucleus (SDCN) to electrical stimulation of pelvic nerve, tibial nerve or mechanical stimulation of perianal region, respectively were recorded extracellularly with glass microelec-trodes. Of the 80 units of SDCN, 13 were identified as non-responsive units. The response patterns of electrical stimulation to the nerves were divided into 3 classes: responses with long-latency and prolonged after-discharges, responses with short-latency and prolonged after-discharges, responses followed by inactiva-tions of spontaneous discharges. Among 67 units which were found to be responsive to the nerve and perianal region stimulation, 32 units (47. 76%) responded exclusively to somatic stimulation, and 5 units (7. 46%) responded selectively to stimulation of the pelvic nerve. The remaining 30 units (44. 78%) received con-...