Modulation of a dog's internal organ function by selective stimulation of the splanchnic nerve

The superficial regions of the dog splanchnic nerve were selectively stimulated with 33-electrode spiral cuffs in 11 circumferential groups of three electrodes to modulate the function of the innervated internal organs and glands. In two adult Beagle dogs under general anaesthesia, the cuffs were chronically implanted on the nerve trunks before the celiac ganglion. Superficial regions of the nerves were selectively stimulated for 15 s with biphasic, rectangular, current pulses (2 mA intensity, 200 micros duration, and 20 Hz frequency) which were delivered sequentially to the corresponding group of three electrodes. The results showed that Group no. 8 of three electrodes elicited the highest influence on pressure within the bladder. Namely, a decrease in pressure starting from 34.97 mmHg at the beginning of stimulation to 34.92 mmHg at the end of stimulation was observed. It was also shown that only Group no. 4 of three electrodes significantly modified the endocrine function of the pancreas. A considerable increase in glucagon secretion with a peak value of 47 pg/ml and an insignificant change in insulin secretion were also observed. The results of histological observations demonstrated that the use of the cuff was associated with a buildup of connective tissue encapsulation around the cuff as well as within it. However, functional deficits were not observed in the animal, and most of the fibers appeared to be histologically normal after stimulation. The results of this study clearly demonstrate that internal organs and glands can be selectively stimulated through the selective stimulation of innervating superficial regions of the autonomous peripheral nerve.