title: One GABA and two acetylcholine receptors function at the C. elegans neuromuscular junction.
abstract: We describe an electrophysiological preparation of the neuromuscular junction of the nematode C. elegans, which adds to its considerable genetic and genomic resources. Mutant analysis, pharmacology and patch-clamp recording showed that the body wall muscles of wild-type animals expressed a GABA receptor and two acetylcholine receptors. The muscle GABA response was abolished in animals lacking the GABA receptor gene unc-49. One acetylcholine receptor was activated by the nematocide levamisole. This response was eliminated in mutants lacking either the unc-38 or unc-29 genes, which encode alpha and non-alpha acetylcholine receptor subunits, respectively. The second, previously undescribed, acetylcholine receptor was activated by nicotine, desensitized rapidly and was selectively blocked by dihydro-beta-erythroidine, thus explaining the residual motility of unc-38 and unc-29 mutants. By recording spontaneous endogenous currents and selectively eliminating each of these receptors, we demonstrated that all three receptor types function at neuromuscular synapses.
authors.affiliation: Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, Utah 84112-0840, USA. richmond@biology.utah.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Richmond
authors.forename: E M
authors.initials: EM
authors.lastname: Jorgensen
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000502:physiology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D017238:Genes, Helminth; D007978:Levamisole / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009469:Neuromuscular Junction / Q000502:physiology*; D009538:Nicotine / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D011950:Receptors, Cholinergic / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D018079:Receptors, GABA / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000502:physiology; D019789:Tetraethylammonium / Q000494:pharmacology
chemical_list: D015220:Calcium Channels; D015221:Potassium Channels; D011950:Receptors, Cholinergic; D018079:Receptors, GABA; D011978:Receptors, Nicotinic; D007978:Levamisole; D019789:Tetraethylammonium; D009538:Nicotine; D015761:4-Aminopyridine