title: GABA-mediated modulation of ATP-induced intracellular calcium responses in nodose ganglion neurons of the rat.
abstract: We examined ATP-induced intracellular Ca(2+) ([Ca(2+)]i) responses in the neurons and satellite cells from one of the viscerosensory ganglia, the nodose ganglion (NG), as well as the GABA-mediated modulation of ATP-induced neuronal [Ca(2+)]i responses using intracellular calcium imaging. In neurons with satellite cells, ATP induced [Ca(2+)]i increases in both the neurons and satellite cells. The P2X receptor agonist, α,β-meATP, induced [Ca(2+)]i increases in neurons and this response was inhibited by the P2X receptor antagonist, PPADS. On the other hand, the P2Y receptor agonist, ADP, induced [Ca(2+)]i increases in satellite cells, and this response was inhibited by the P2Y receptor antagonist, MRS2179. RT-PCR detected the expression of P2X2, P2X3, P2Y1, and P2Y2 receptor mRNAs in NG extracts. Immunohistochemistry revealed that NG neurons and satellite cells were immunoreactive to P2X2 and P2X3, and P2Y1 and P2Y2 receptors, respectively. In isolated neurons, the ATP-evoked [Ca(2+)]i increase was inhibited by GABA. However, in neurons with satellite cells, the GABAA receptor antagonist, bicuculline, enhanced the ATP-induced [Ca(2+)]i increase in neurons. These results suggest that viscerosensory neuronal excitability may be modulated by GABA from satellite cells in NG.
authors.affiliation: Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan; Department of Basic Veterinary Science, United Graduate School of Veterinary Science, Gifu University, Gifu, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Yokoyama
authors.affiliation: Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan.
authors.forename: Shou
authors.initials: S
authors.lastname: Fukuzumi
authors.affiliation: Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Hayashi
authors.affiliation: Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan; Department of Basic Veterinary Science, United Graduate School of Veterinary Science, Gifu University, Gifu, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Nakamuta
authors.affiliation: Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan; Department of Basic Veterinary Science, United Graduate School of Veterinary Science, Gifu University, Gifu, Japan. Electronic address: yyoshio@iwate-u.ac.jp.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamamoto
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D042541:Intracellular Space / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009620:Nodose Ganglion / Q000166:cytology / Q000378:metabolism*; D058911:Purinergic P2X Receptor Agonists / Q000494:pharmacology; D058912:Purinergic P2Y Receptor Agonists / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D017208:Rats, Wistar; D058469:Receptors, Purinergic P2X / Q000235:genetics / Q000378:metabolism; D058470:Receptors, Purinergic P2Y / Q000235:genetics / Q000378:metabolism; D027161:Satellite Cells, Perineuronal / Q000187:drug effects / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D058787:GABA-A Receptor Antagonists; D058911:Purinergic P2X Receptor Agonists; D058912:Purinergic P2Y Receptor Agonists; D012333:RNA, Messenger; D058469:Receptors, Purinergic P2X; D058470:Receptors, Purinergic P2Y; D005680:gamma-Aminobutyric Acid; D000255:Adenosine Triphosphate; D002118:Calcium
keywords: ATP; GABA; Nodose ganglion; Satellite cell; Sensory neuron