| The restraint water-immersion stress (RWIS) rat model is widely used to study the stress-induced gastric ulcer and to find the medicine that can cure this disease.The results of many experiments indicated that the RWIS -induced gastric ulcer was mostly due to the parasympathetic hyperactivity that control the stomach while other stresses induced the enhancement of hypothalamo- pituitary- adrenocortical axis (HPA axis) and sympathetic- adrenomedullar(SA). Parasympathetic nerve innervating the stomach is the vagal nerve which are largely from dorsal motor nucleus of the vagus(DMV)and partly from nucleus of solitary tract (NTS).As the center of parasympathetic preganglionic neurons,DMV and NTS all regulate gastric motility.However,there are no unanimous standpoints about the excited or inhibitory effects of DMV and NTS on the gastric motility by now.To clarify the effects of the two nucleus on gastric motility,our research group has electrically stimulated them respectively and found that they all inhibited gastric motility.Whether excitement of neuron body or excitement of passed fibres conduced to these inhibiting results was unclear.So,in this study,we observed the discharge of nerve cell and Fos expression in each neuro-neucleus of NTS and DMV of rats in RWIS,to investigate the relation between this stress and the excitement of neuro-neucleus in the brainstems of rats.This research include three parts: The first part, To observe the effect of capsaicin on c-fos expression in brainstem nuclei and gastric ulcer in water immersion-restraint stress in rats. The rats with capsaicin injection were restrained and immersed in water, to observe the expression of c-FOS protein in the brainstem nuclei by the immunocytochemical method and to measure gastric ulcer index. Compared with the saline control group, the expression of c-fos protein in capsaicin group decreased significantly(P<0.01). and the gastric ulcer index reduced significantly(P<0.05).These results suggest that DMV, NTS and capsaicin-sensitive afferent nerves participate in the process of gastric mucosal injury induced by water immersion-restraint stress .The second part,To observe the discharge situation of dorsal vagal nucleus and nucleus of the solitary tract at lower temperature of the rat gastric.The discharge frequency of neurons is used as a indicator of the exciting neurons. The main aim of this part is to study the change of discharge at NTS and DMV after injection of 4℃normal saline. Results: Compared with the control group,the discharge frequency of DMV neurons significantly (P<0.05) increase after reperfusion with 4℃normal saline,and the discharge frequency of NTS neurons increase after after reperfusion with 4℃normal salinea , but the difference was not significant .The third part,To study c-Fos expression in the DMV and NTS after Lower temperature on the rat stomach. This section we use c-Fos expression as a sign of nerve cell irritability, The main aim is to study the expression of c-Fos in NTS and DMV after injection of 4℃normal saline. Results: Compared with the control group ,the c-fos expression of DMV neurons significantly increased(P <0.05) after reperfusion with 4℃normal saline, and the c-Fos expression of NTS neurons also significantly increased(P <0.01) after reperfusion with 4℃normal saline .
|
PDF Full Text Request