THE ACTION POTENTIAL OF BOWELS IN RABBITS SUBJECTED TO THE STIMULATION OF THE CORTICAL AREAS

Abstract

In order to investigate the correlation between the cortical function and the motility of bowels, the responses of the action potentials in bowels to the cutting or stimulation of several cortical areas were observed.Rabbits were anesthetized with urethane. In some of them, the rostral portions of diencephalons were cut and in the others, electrical or chemical (1-glutamate) stimuli were given to the following cortical areas which seem to be closely correlated with the autonomic nervous system; prefrontal area, gyrus cinguli anterior, gyrus cinguli posterior and hypocampus. The action potentials were recorded from the serous membrane sides of duodenum and ileum by means of bipolar metal electrodes. The results obtained were as follows:1. By cutting off the rostral portions of diencephalons, the increase in amplitude of action potential, the appearance of large spikes (200μV or more) and the prolongation of the duration of the burst were observed.2. By stimulation of the prefrontal area, gyrus cinguli anterior and hypocampus, spike potentials increased its amplitude and prolonged its duration. On the other hand, stimulation of gyrus cinguli posterior depressed the action potential.3. After cutting off the vagi at the level of the neck, stimulation of cortical areas was ineffective to produce the remarkable change in action potentials of bowels.