Cortical Projection of Afferent Impulses from the Distal Colon via the Pelvic Nerve in the Dog
The cortical projection of the colonic afferent impulse in the pelvic nerve was studied in dogs anesthetized with chloralose. After afferent stimulation of the right rectal branches of the pelvic nerve, initial positive waves were evoked on restricted areas of the precuneus, posterior sigmoid, postcruciate, anterior sylvian, anterior ectosylvian, anterior sigmoid, medial frontal and cingulate gyri. The shortest latency of the waves was 12 msec in the first five of these gyri. The threshold intensity of the afferent stimulation for the evoked potentials was one third of that for the reflex discharges of the rectal branch.