[Relation between the electrophysiological activities of the digestive viscera and the signals received from the abdominal wall. Initial results in the waking rat].

Experiments in the unanesthetized rats were made to examine the possibilities of relations between visceral and abdominal sites of electrodes implantation. From gastric duodenal ileal electrodes wire, relations may be observed with the surface records with the following limitation: in the frequencies greater than or equal to 200 cycles/mn ("A" range) the spiking visceral activity is never found from surface derivation where the EKG is frequently present. In the ranging of 60 to 80 cycles/mn correspondences of the signals are in relation with respiratory transmission. The slower frequencies from surface activity (longlasting RC time constant of 6 s are used) concern duodenal (38,8 +/- 0,98 cycles/mn) and ileal (28,6 +/- 1,9 cycles/mn) slow waves activities may be recognized in the sequences during several minutes in alternation with the C type activities. In such conditions of typical correspondences, it may be noticed modifications of signal during the viscero-parietal transmission: attenuation (averaging 0,7); dephasage of 5 to 12 seconds (swing to strong capacitive component acting as an active filter) and mixing with others activities not be identified. The methodological interest for a non invasive characterization of visceral physiological states is discussed.