Premium
Neurochemical Phenotype of Afferent Neurons of the Nucleus Tractus Solitarius in Response to Esophageal Distension in the Rat
Author(s) -
Ambler Jason,
Babic Tanja,
Travagli R.Alberto
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.1002.6
Subject(s) - distension , esophagus , solitary nucleus , medicine , brainstem , metabotropic glutamate receptor , endocrinology , chemistry , glutamate receptor , receptor
The nucleus tractus solitarius (NTS) receives visceral information from the gastrointestinal, cardiovascular and respiratory systems via type‐A and type‐C fibers. NTS nucleus centralis (cNTS) receives afferent inputs from the esophagus and previous studies have shown that esophageal afferents display diverse properties. It has also been shown that gastro‐esophageal vagal fibers are under modulatory control of group III metabotropic glutamate receptors (mGluRs). The aim of this study was to determine whether esophageal distention activates cNTS neurons that express group III mGluRs. Rats were anesthetized and an esophageal balloon was placed 5 mm from the lower esophageal sphincter. The esophagus was extended for 1s every 10s for 30min. 90min following esophageal distention, rats were perfused with saline, followed by 4% paraformaldehyde. Brainstem sections were reacted for c‐fos and mGluR8 immunoreactivity (IR). In five control rats, 8±1.8 NTS neurons/section were c‐Fos IR and 9±2.3% were also mGluR8 IR. In cNTS, 0.2±0.05 neurons/section were labelled for c‐fos, 5.7±2% of these neurons were also labelled for mGluR8. Following esophageal distension, 17±3.1 NTS neurons/section were c‐Fos IR and 22±1.5% were also mGluR8 IR (p<0.05 vs. control for both). In cNTS, 2.9±0.5 neurons/section were labelled for c‐fos, i.e. 27±1.9 % of these neurons were also labelled for mGluR8 (p<0.05 vs. control for both). These data show that esophageal distension activates mGluR8‐ir neurons in cNTS, suggesting that integration of sensory inputs from the esophagus may be modulated by group III mGluRs. Supported by NIH grant DK‐55530 and a “Frontiers in Physiology Research Teacher Professional Development Fellowship Award” from APS