Experimental Study Of Distribution And Function Of Th- And HAP1-Immunoreactive Positive Neurons In Visceral Motor Ganglia In Rat

Distribution of Huntinting-associated protein 1 (HAP1) in central nervous system has been reported in many literatures. In peripheral nervous system, Min Liao et al reported that HAP1 distributed in spinal ganglia and trigeminal ganglia. In visceral nervous system HAP1 was only found in the embryonic intestinal intramural ganglia and the abdominal sympathetic ganglia of the mouse. In order to research the distribution of HAP1 in the visceral motor ganglia of the adult rat, we had studied distribution of HAP1 in the intrinsic cardiac ganglia, lung ganglia, pelvic ganglia and sympathetic trunk ganglia. Tyrosine hydroxylase (TH) is the rate-limiting enzyme of catecholamine synthesis. In order to study whether TH widely distributed in visceral motor ganglia, we had studied distribution of TH in the intrinsic cardiac ganglia, lung ganglia, alimentary intramural ganglia and pelvic ganglia; and also studied the co-localization of HAP1 and TH in the pelvic ganglia and intrinsic cardiac ganglia, intend to provide morphological evidence for studying the effects of HAP1 and TH in the visceral motor ganglia.Immunohistochemical method was used in this experiment to study the distribution and morphology of HAP1-IR ganglia in the intrinsic cardiac ganglia, lung ganglia, pelvic ganglia and sympathetic trunk ganglia of the rat and the distribution and morphology of TH-IR ganglia in the intrinsic cardiac ganglia, lung ganglia, alimentary intramural ganglia and pelvic ganglia. We also chose continuous slices of the pelvic ganglia and intrinsic cardiac ganglia to study the co-localization of HAP1 and TH in the neurons of the pelvic ganglia and intrinsic cardiac ganglia.The result revealed that under light microscope considerable HAP1-IR positive neurons were seen in the intrinsic cardiac ganglia, lung ganglia, pelvic ganglia and sympathetic trunk ganglia. The HAP1-IR products were brown, localized in cytoplasm and the nuclei were negative. The HAP1-IR positive neurons were round,elliptic or polygonal. The number of the neurons in the pelvic ganglia and sympathetic trunk ganglia was large, and there were many HAP-IR positive neurons in those ganglia. The intrinsic cardiac ganglia and lung ganglia distributed in the loose connective tissue of the posterior wall of atria and the hilum of lung respectively, and the number of HAP1-IR positive neurons was less. TH-IR positive neurons extensively distributed in the intrinsic cardiac ganglia of the young rats (4-5w), lung ganglia, alimentary intramural ganglia and pelvic ganglia of adult rats. The TH-IR products were also brown, localized in cytoplasm and the nuclei were negative. The morphology of TH-IR positive neurons in the intrinsic cardiac ganglia and pelvic ganglia were similar to that of the HAP1-IR positive neurons in the same ganglia. The TH-IR positive neurons in the alimentary intramural ganglia were comparatively large, scattered among muscular layers, and had obvious process. In the continuous slices of the pelvic ganglia and the intrinsic cardiac ganglia, the HAP1-IR positive neurons were also TH-IR positive, and only HAP1-IR positive or TH-IR positive neuron was not found.HAP1 widely distributed in the visceral motor ganglia, which suggested that HAP1 probably involved in some function adjustments of vegetative nervous system. TH has been found in many classic parasympathetic ganglia. This result suggested that those classic parasympathetic neurons can synthesize catecholamine transmitter and are sympathetic. The significance of co-localization HAP1 and TH in the neurons of the pelvic ganglia and the intrinsic cardiac ganglia was not clear. It is deserved to study if HAP1 and TH have some interactions in same neuron.