ABSTRACT
BACKGROUND: Using c-fos expression one of the immediate early gene, as a marker of altered neuronal response, we investigated the effect of superior cervical ganglion block (SCGB) exhibiting the same effect of SGB of human on the activity of several brain regions which are considered as located on autonomic neural pathway and neuroendocrine axis in rat. METHOD: The 48 Sprague-Dawley strain rats were divided into 4 groups, as saline/stress (control) group, SCGB/stress (tested) group, saline group, SCGB group. Superior cervical ganglion block was conducted in the SCGB/stress group and SCGB group while saline/stress and saline group were sham operated. After then restraint stress was imposed on the animals of SCGB/stress group and saline/stress group. And 2 hour after injection (saline, SCGB group) or restraint stress (saline/stress, SCGB/stress group), c-fos protein (Fos) was localized by immunocytochemistry. RESULTS: Much stronger Fos immunoreactivity was induced in the several brain region of control group rats compared to other three groups and the numbers of Fos positive cell count of tested group were significantly decreased in paraventricular hypothalamic nucleus (p<0.01), A5 (p<0.01), raphe pallidus (p<0.05), nucleus tractus solitaius (p<0.01) compared to control group. CONCLUSION: This study demonstrate that superior cervical ganglion block attenuates stress induced neuronal activities of paraventricular hypothalamic nucleus, A5, raphe pallidus, nucleus tractus solitarius.