Identification of acetylcholine receptors in adult rat trigeminal ganglion neurons.
Nicotinic acetylcholine receptors (nAChRs) were identified in a subpopulation of cultured adult rat trigeminal ganglia (TG) neurons by whole-cell patch-clamp recordings. Dimethylphenylpiperazinium (DMPP), a nAChR agonist, induced inward currents in 21/68 of TG neurons having soma diameters greater than 28 microns. These currents were inhibited by hexamethonium, mecamylamine and atropine, indicating the presence of neuronal ganglionic-type nAChRs. This interpretation is consistent with the finding that the nicotine- or DMPP-induced currents were not inhibited by alpha-bungarotoxin (alpha-Bng) in 5 of the 9 cells tested with this compound. However, in 2 of the 9 cells tested, the DMPP-induced currents were completely inhibited by alpha-Bng, and in the remaining two cells tested, the currents were partially inhibited by alpha-Bng. About 22% of the cells having diameters > or = 28 microns were specifically labeled with FITC-labeled alpha-Bng, whereas only 2% of the cells with soma diameters < 28 microns were labeled. These data taken together suggest that more than one subtype of nAChR is present in TG.
Department of Neurobiology, Duke University Medical Center, Durham, NC 27710.
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D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D004246:Dimethylphenylpiperazinium Iodide / Q000494:pharmacology; D005260:Female; D005727:Ganglia, Spinal / Q000187:drug effects*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009412:Nerve Fibers / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011950:Receptors, Cholinergic / Q000032:analysis*; D012668:Trigeminal Ganglion / Q000737:chemistry* / Q000166:cytology / Q000187:drug effects
D011950:Receptors, Cholinergic; D004246:Dimethylphenylpiperazinium Iodide; D000109:Acetylcholine