Y X Dong1, K H Xiong1, Z R Rao1, J W Shi1. 1. Yuan-Xiang Dong, Kang-Hui Xiong, Zhi-Ren Rao, Ji-Wu Shi, Department of Anatomy, The Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China.
Abstract
AIM: To determine whether medullary catecholaminergic neurons expressing Fos induced by chemical stimulation of the stomach project to the paraventricular nucleus of hypothalamus (PVH) in rats. METHODS: Horseradish peroxidase (HRP) was introduced stereotaxically into the PVH of rats. Histochemical analysis of coronal sections through the medulla were analyzed using triple-label immunohistochemistry to identify cells that were retrogradely labeled with HRP, Fos (ABC method), and tyrosin hydroxylase (TH) (PAP method). RESULTS: Seven kinds of labeled neurons were found in the nucleus tractus solitarii (NTS), the ventrolateral medulla (VLM) and the reticular formation (RF) of the medulla: Fos-like immunoreactive (FosLI) neurons, TH-like immunoreactive (TH-LI) neurons and HRP retrogradely single-labeled neurons, FosLI/HRP, FosLI/TH-LI and HRP/TH-LI double-labeled neurons, and FosLI/HRP/TH-LI triple-labeled neurons. CONCLUSION: Ascending projections from the NTS, VLM and RF to the PVH might be involved in the transmitting process of visceral noxious stimulation.
AIM: To determine whether medullary catecholaminergic neurons expressing Fos induced by chemical stimulation of the stomach project to the paraventricular nucleus of hypothalamus (PVH) in rats. METHODS:Horseradish peroxidase (HRP) was introduced stereotaxically into the PVH of rats. Histochemical analysis of coronal sections through the medulla were analyzed using triple-label immunohistochemistry to identify cells that were retrogradely labeled with HRP, Fos (ABC method), and tyrosin hydroxylase (TH) (PAP method). RESULTS: Seven kinds of labeled neurons were found in the nucleus tractus solitarii (NTS), the ventrolateral medulla (VLM) and the reticular formation (RF) of the medulla: Fos-like immunoreactive (FosLI) neurons, TH-like immunoreactive (TH-LI) neurons and HRP retrogradely single-labeled neurons, FosLI/HRP, FosLI/TH-LI and HRP/TH-LI double-labeled neurons, and FosLI/HRP/TH-LI triple-labeled neurons. CONCLUSION: Ascending projections from the NTS, VLM and RF to the PVH might be involved in the transmitting process of visceral noxious stimulation.