Character of the spike activity on both sides of duodenal transection depending on the regeneration of the intrinsic nervous system.

Experiments are carried out on dogs with transection of the duodenum followed by end-to-end anastomosis and chronically implanted silver ball-shaped electrodes on the muscle wall of the stomach and on the segments of the duodenum proximal and distal to the transection. Dissociation of the spike activity of the two duodenal segments is established after the operation. As early as the second week after the transection, parallel with this single group of spike potentials propagating through the anastomosis are also observed. With increasing the time interval from the operation propagation of the spike activity along the length of the muscle occurs more and more frequently. The difference in the percentage of spike activity of the two duodenal segments is greatest during the first and second months after the operation. At the beginning of the third month it decreases gradually to reach 10 per cent approximately during the fifth month after the operation. In preliminary vagotomized dogs the difference in the percentage of the spike activity is maintained around 20-30 per cent. In dogs with definitely separated segment of the duodenum this difference becomes great and there are no tendencies towards reduction even in the sixth month post operation. Histological studies of the material taken from the area of the anastomosis of animals at different post-transection periods, subjected to silver impregnation after the method of Bielschowsky-Gross, show regeneration of the severed nerve bundles of plexus myentericus Auerbachi. The restoration of the spreading of the spike activity along the length of the duodenum is associated with restoration of the nerve structures in the muscle wall of the duodenum.