Neuronal activity of the medulla oblongata revealed by manganese-enhanced magnetic resonance imaging in a rat model of gastroesophageal reflux-related cough.

摘要

We investigated neuronal activity of the medulla oblongataduring gastroesophageal reflux-related cough (GERC). A ratmodel of GERC was generated by perfusing HCl into loweresophagus and inducing cough with citric acid. The HCl group ratwas received HCl perfusion without citric acid-induced cough.The saline control rat was perfused with saline instead and coughwas induced. Citric acid-induced cough rat was only induced bycitric acid. Blank group rats were fed normally. Fos expressionswere observed in medulla oblongata nuclei usingimmunohistochemistry. Manganese-enhanced magneticresonance imaging (MEMRI) was performed to detect theMn2+ signal following intraperitoneal injection of MnCl2. HClperfusion and citric acid-induced cough caused Fos expressions inthe nucleus of solitary tract (nTS), dorsal motor nucleus of thevagus (DMV), paratrigeminal nucleus (Pa5), and intermediatereticular nucleus (IRt), which was higher than HCl group, salinecontrol group, citric acid-induced cough group, and blank group.A high Mn2+ signal was also observed in most of these nuclei inmodel rats, compared with blank group animals. The Mn2+ signalwas also higher in the HCl, saline and citric acid-induced coughgroup animals, compared with blank group animals. The studyshowed medulla oblongata neurons were excited in a HClperfusion and citric acid-induced cough rat model, and nTS, DMV,Pa5 and IRt neurons maybe involved in the cough process andsignal integrate.