Recording of electroneurograms from the nerves innervating the pancreas of a dog.
Electroneurograms (ENGs) from the vagus, splanchnic and pancreatic nerves innervating the pancreas of a dog, were recorded with chronically implanted silicone multi-electrode circular cuffs in an intact pancreas and in a pancreas partly disabled with alloxan. The cuffs contained 33 platinum electrodes (0.6x1.5 mm) arranged in three parallel circular groups integrated into the inner surface of the cuff. Each circular group contained 11 electrodes at a distance of 0.5 mm apart, with 6 mm between the circular groups. The cuffs had an inner diameter of 2.5 mm and the length of 18 mm. In a 2-year study, the cuffs were implanted into two adult Beagle dogs (one female and one male). In the vagus nerve, the cuff was installed on the nerve at the neck, whilst in the splanchnic nerve, the cuff was installed on the nerve before the celiac ganglion, and in the pancreatic nerve, the cuff was installed on the nerve just before it enters the pancreas. In each of the three implanted cuffs, the electrodes of the central circular group were connected to each other and this signal provided one input to a multi-channel ENG amplifying system. The electrodes of each of the two outer spiral groups were connected to each other and then both these groups were short-circuited. This signal then provided another input to the multi-channel ENG amplifying system. The ENG amplifying system was designed to amplify the ENGs 100000 times and to pass frequencies of between 500 and 10 kHz. In our study, three recordings in each animal were conducted. Recordings in the intact pancreas were conducted 2 and 6 months after the implantation, while the recording in the partly disabled pancreas, was conducted 10 months after the implantation and 10 days after the disablement. Due to the fact that the results obtained in both animals were actually quite similar, we present the results of the recordings obtained in one animal. In both animals the cuffs were left implanted for more than 1 year and were used for pancreatic stimulation, although this is not in this paper. The results show that cuffs implanted chronically on the nerves innervating the pancreas of a dog could reliably record the ENGs. This information could be used effectively in further study of pancreatic innervation and its function. Moreover, the results suggest that cuffs could also be useful in recording the ENGs from other nerves of the autonomic nervous system that innervate various glands and internal organs.
Rozman
J
J
ITIS d. o. o. Ljubljana, Centre for Implantable Technology and Sensors, Lepi pot 11, 1000, Ljubljana, Slovenia. janez.rozman@guest.arnes.si
Zorko
B
B
Bunc
M
M
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D004285:Dogs / Q000033:anatomy & histology / Q000502:physiology*; D004567:Electrodes, Implanted / Q000592:standards*; D004594:Electrophysiology / Q000295:instrumentation* / Q000379:methods; D009431:Neural Conduction / Q000502:physiology*; D010179:Pancreas / Q000294:innervation* / Q000378:metabolism; D013153:Splanchnic Nerves / Q000502:physiology; D014630:Vagus Nerve / Q000502:physiology; D017833:Visceral Afferents / Q000502:physiology*