title: Esophagocardiac convergence onto thoracic spinal neurons: comparison of cervical and thoracic esophagus.
abstract: The aim of this study was to characterize thoracic spinal neurons receiving convergent inputs from the esophagus, heart and somatic receptive fields. Extracellular potentials of single T3-T4 spinal neurons were recorded in pentobarbital anesthetized male rats. Thoracic and cervical esophageal distensions (TED, CED) were produced by water inflation of a latex balloon. A catheter was placed in the pericardial sac to administer bradykinin or a mixture of algogenic chemicals. 96/311 (31%) neurons responded to both TED and intrapericardial chemicals (IC) and 48/177 (27%) neurons responded to both CED and IC. Long-lasting excitatory responses were more frequently encountered (P<0.05) in esophagocardiac spinal neurons responding to TED (T-ECSNs, 62/91) than in neurons responding to CED (C-ECSNs, 23/47). Ninety-one percent of T-ECSNs and 98% of C-ECSNs had somatic fields on chest, axilla and upper back areas. Esophagocardiac convergence on thoracic spinal neurons provided a spinal mechanism that might mediate viscerovisceral nociception and reflexes.
authors.affiliation: Department of Physiology, University of Oklahoma Health Sciences Center, P.O. Box 26901, Oklahoma City, OK 73190, USA. chao-quin@ouhsc.edu
authors.forename: Chao
authors.initials: C
authors.lastname: Qin
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Chandler
authors.forename: Robert D
authors.initials: RD
authors.lastname: Foreman
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D004947:Esophagus / Q000294:innervation* / Q000502:physiology*; D006321:Heart / Q000294:innervation* / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology; D010146:Pain / Q000139:chemically induced; D010812:Physical Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*