Objective To investigate the distribution relationship of microglia and neuron in rat medullary visceral zone(MVZ) after stomatic nociception. Methods After 2ml formalin(2.5%)injection in rat stomach by tiny plastic tube,Anti-Fos protein(labeling neuron)and anti-OX 42(labeling microglia)single and double immunohistochemical ABC method staining on model medulla oblongata sections in different time point(0.5h,1h,2h and 3h) were used. Results 1.After wakefulness,the animal models appear restlessness and agitation in 1-2h.2.We found hemorrhage and exfoliation in model's gastric mucosa.3.Fos positive neurons and OX 42 positive microglias were observed in MVZ,whose distribution was congruous and appeared clearly character of locations.4.The results of immunochemical diplex staining indicate that many Fos positive neurons were surrounded by intensive OX 42positive microglias.5.OX 42 positive microglia showed a tendency,which increased in 0.5-2h and decreased in 3h.Conclusion Neurons and microglia in MVZ may be involved in visceral nociception transfer and adjustment function.

Objective To investigate the early effect of medium-dose ionic irradiation on the expression of Fos protein in the rat brain. Methods Fos protein was observed in rat brains at times ranging from 24 hours to 4 weeks after hemispheric irradiation (single-fraction maximal dose of 20Gy) with the immunohistochemical technique. Results Compared with that of the un-radiated rats,the expression of Fos protein in the irradiated brain decreased distinctly 24 hours and 1 week after irradiation.However,the quantity of Fos immunopositive cells increased gradually afterwards.At four weeks after radiation,expression of Fos protein recovered progressively in medulla oblongata and pons,in which Fos immunopositive cells were more than those in control group.In contrast,expression level of Fos protein in mesencephalon,diencephalons or telencephalon was still less compared with that of the un-irradiated rats.Conclusion The result suggested that the neuronal activity might be inhibited in certain nuclei of the rat brain in early stages after hemisphere irradiation,and this inhibitory phenomenon was more obviously in higher neural centers.