Effects of Restraint Water-immersion Stress (RWIS) on Fos Expression in the Spinal Cord and Brainstem in Rats

The rat restraint - soaking stress (restraint water-immersion stress RWIS) model has been widely used to study the occurrence of stress-induced gastric mucosal injury mechanism and clinical treatment of drug screening. Numerous experimental results show that: the state of bondage - water immersion stress (RWIS) stomach hyperkinesia, increased gastric acid secretion was mainly due to the strengthening of parasympathetic activity dominated the stomach. This is due to a variety of other types of stress hypothalamic - pituitary - adrenal cortical axis and sympathetic - adrenal medullary system activity to strengthen the opposite phenomenon; bondage - water immersion stress model parasympathetic of activities to strengthen, while these parasympathetic from the medullary dorsal vagal nucleus and nucleus ambiguus. Vagus the dorsal nuclear (DMV) suspected nuclear (NA), nucleus of solitary tract (NTS) on gastric motility as the primary hub of parasympathetic regulation or inhibition of excitatory effects, reported in the literature is quite inconsistent. In order to figure out the three nuclei of gastric motility in the end, what kind of role in front of the laboratory work of electrical stimulation or chemical stimulation of the three nuclei, found that the three nuclei of stimulated gastric motility are a disincentive. Well, these nuclei in the rat restraint - soaking stress is excited or suppression? Spinal cord gray matter after angle, rake angle, side angle of nerve element is excited or suppression? In this paper, the immediate early gene c-fos expression of Fos protein flag as neuronal activation, bondage - flooding stress individual nerve nuclei in different time periods in the rat spinal cord and brainstem neuronal excitability, contact the degree of gastric ulcers in rats to further explore the spinal cord and brainstem The relationship between the various nuclei excited with RWIS. The experiment was divided into two parts. Experimental Study I: The experimental rats were randomly divided into five groups, the rats bondage - flooding stress time were 0 min, 30 min, 60 min, 120 min, 180 min, the first group as a control group. After removing excess sodium pentobarbital anesthesia, cardiac perfusion, the spinal cord and brain stem, post-fixed overnight, frozen sections, slice thickness of 25μm. Slices do Fos immunohistochemistry. The results showed that the expression in the spinal cord, the posterior horn and brainstem nuclei (NTS, DMV, AP, SubP, LC, PBN, CGO, LRt-PC, etc.), Fos-like immunoreactive cells have a very significant not exactly the same, but the number and intensity of its expression, and as RWIS time prolonged, Fos expression presents a certain regularity. Overall, 60 min stress rat brain stem and spinal cord in Fos expression peaked, but specific to each nucleus, and slightly different. With time after, animals adapt to decreased expression of Fos. Experimental study II: cut off the rat diaphragm vagus nerve RWIS 180 min. Found that the vagus nerve and then RWIS cut diaphragmatic rat brainstem nuclei in Fos expression was significantly decreased, while the expression of the spinal cord has been enhanced. The gastric mucosa Ministry almost no ulcer. The results of this study show that: RWIS rat spinal anterior horn of the different time periods, posterior horn and brainstem nuclei have different levels of Fos expression in the spinal anterior horn; for RWIS 30-60 min, most of the posterior horn and brainstem nuclear group of Fos expression peaked. Then gradually decreased; discovery cut diaphragmatic vagus nerve after RWIS 180 min, significantly reduced Fos expression in the rat brainstem nuclei, enhanced expression of the spinal cord.