title: Electrical coupling and innexin expression in the stomatogastric ganglion of the crab Cancer borealis.
abstract: Gap junctions are intercellular channels that allow for the movement of small molecules and ions between the cytoplasm of adjacent cells and form electrical synapses between neurons. In invertebrates, the gap junction proteins are coded for by the innexin family of genes. The stomatogastric ganglion (STG) in the crab Cancer borealis contains a small number of identified and electrically coupled neurons. We identified Innexin 1 (Inx1), Innexin 2 (Inx2), Innexin 3 (Inx3), Innexin 4 (Inx4), Innexin 5 (Inx5), and Innexin 6 (Inx6) members of the C. borealis innexin family. We also identified six members of the innexin family from the lobster Homarus americanus transcriptome. These innexins show significant sequence similarity to other arthropod innexins. Using in situ hybridization and reverse transcriptase-quantitative PCR (RT-qPCR), we determined that all the cells in the crab STG express multiple innexin genes. Electrophysiological recordings of coupling coefficients between identified pairs of pyloric dilator (PD) cells and PD-lateral posterior gastric (LPG) neurons show that the PD-PD electrical synapse is nonrectifying while the PD-LPG synapse is apparently strongly rectifying.
authors.affiliation: Volen Center and Biology Department, Brandeis University, Waltham, Massachusetts; and.
authors.forename: Sonal
authors.initials: S
authors.lastname: Shruti
authors.affiliation: Division of Biological Sciences, University of Missouri at Columbia, Columbia, Missouri.
authors.forename: David J
authors.initials: DJ
authors.lastname: Schulz
authors.affiliation: Division of Biological Sciences, University of Missouri at Columbia, Columbia, Missouri.
authors.forename: Kawasi M
authors.initials: KM
authors.lastname: Lett
authors.affiliation: Volen Center and Biology Department, Brandeis University, Waltham, Massachusetts; and.
authors.forename: Eve
authors.initials: E
authors.lastname: Marder
mesh_terms: D000818:Animals; D003386:Brachyura; D017630:Connexins / Q000235:genetics / Q000378:metabolism*; D054351:Electrical Synapses / Q000378:metabolism / Q000502:physiology*; D017952:Ganglia, Invertebrate / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D008121:Nephropidae; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D013270:Stomach / Q000294:innervation; D059467:Transcriptome
chemical_list: D017630:Connexins
keywords: crustaceans; electrical synapses; gap junctions; phylogeny; reverse transcriptase-quantitative PCR