Published online Jun 15, 1997. doi: 10.3748/wjg.v3.i2.72
Revised: January 31, 1997
Accepted: March 1, 1997
Published online: June 15, 1997
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.