title: Molecular and functional asymmetry at a vertebrate electrical synapse.
abstract: Electrical synapses are abundant in the vertebrate brain, but their functional and molecular complexities are still poorly understood. We report here that electrical synapses between auditory afferents and goldfish Mauthner cells are constructed by apposition of hemichannels formed by two homologs of mammalian connexin 36 (Cx36) and that, while Cx35 is restricted to presynaptic hemiplaques, Cx34.7 is restricted to postsynaptic hemiplaques, forming heterotypic junctions. This molecular asymmetry is associated with rectification of electrical transmission that may act to promote cooperativity between auditory afferents. Our data suggest that, in similarity to pre- and postsynaptic sites at chemical synapses, one side in electrical synapses should not necessarily be considered the mirror image of the other. While asymmetry based on the presence of two Cx36 homologs is restricted to teleost fish, it might also be based on differences in posttranslational modifications of individual connexins or in the complement of gap junction-associated proteins.
authors.affiliation: Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Rash
authors.forename: Sebastian
authors.initials: S
authors.lastname: Curti
authors.forename: Kimberly G
authors.initials: KG
authors.lastname: Vanderpool
authors.forename: Naomi
authors.initials: N
authors.lastname: Kamasawa
authors.forename: Srikant
authors.initials: S
authors.lastname: Nannapaneni
authors.forename: Nicolas
authors.initials: N
authors.lastname: Palacios-Prado
authors.forename: Carmen E
authors.initials: CE
authors.lastname: Flores
authors.forename: Thomas
authors.initials: T
authors.lastname: Yasumura
authors.forename: John
authors.initials: J
authors.lastname: O'Brien
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Lynn
authors.forename: Feliksas F
authors.initials: FF
authors.lastname: Bukauskas
authors.forename: James I
authors.initials: JI
authors.lastname: Nagy
authors.forename: Alberto E
authors.initials: AE
authors.lastname: Pereda
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D017630:Connexins / Q000378:metabolism* / Q000502:physiology; D054351:Electrical Synapses / Q000378:metabolism* / Q000502:physiology; D029941:Fish Proteins / Q000378:metabolism* / Q000502:physiology; D017629:Gap Junctions / Q000378:metabolism / Q000502:physiology; D006054:Goldfish; D009475:Neurons, Afferent / Q000378:metabolism* / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*; D000097004:Gap Junction delta-2 Protein
chemical_list: D017630:Connexins; D029941:Fish Proteins; D000097004:Gap Junction delta-2 Protein; C100585:connexin 35 protein, vertebrate