title: Functional Properties of Dendritic Gap Junctions in Cerebellar Golgi Cells.
abstract: The strength and variability of electrical synaptic connections between GABAergic interneurons are key determinants of spike synchrony within neuronal networks. However, little is known about how electrical coupling strength is determined due to the inaccessibility of gap junctions on the dendritic tree. We investigated the properties of gap junctions in cerebellar interneurons by combining paired somato-somatic and somato-dendritic recordings, anatomical reconstructions, immunohistochemistry, electron microscopy, and modeling. By fitting detailed compartmental models of Golgi cells to their somato-dendritic voltage responses, we determined their passive electrical properties and the mean gap junction conductance (0.9 nS). Connexin36 immunofluorescence and freeze-fracture replica immunogold labeling revealed a large variability in gap junction size and that only 18% of the 340 channels are open in each plaque. Our results establish that the number of gap junctions per connection is the main determinant of both the strength and variability in electrical coupling between Golgi cells.
authors.affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Budapest 1083, Hungary; János Szentágothai School of Neurosciences, Semmelweis University, Budapest 1085, Hungary.
authors.forename: Miklos
authors.initials: M
authors.lastname: Szoboszlay
authors.affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Budapest 1083, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Lőrincz
authors.affiliation: Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, UK.
authors.forename: Frederic
authors.initials: F
authors.lastname: Lanore
authors.affiliation: Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, UK.
authors.forename: Koen
authors.initials: K
authors.lastname: Vervaeke
authors.affiliation: Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, UK. Electronic address: a.silver@ucl.ac.uk.
authors.forename: R Angus
authors.initials: RA
authors.lastname: Silver
authors.affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Budapest 1083, Hungary. Electronic address: nusser@koki.hu.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Nusser
mesh_terms: D000818:Animals; D002531:Cerebellum / Q000166:cytology*; D017630:Connexins / Q000378:metabolism; D003712:Dendrites / Q000502:physiology; D054351:Electrical Synapses / Q000502:physiology*; D005260:Female; D017629:Gap Junctions / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D008297:Male; D051379:Mice; D000097004:Gap Junction delta-2 Protein
chemical_list: D017630:Connexins; D000097004:Gap Junction delta-2 Protein
keywords: cerebellum; connexin36; dendrites; electrical synapses; gap junctions; immunolocalization; interneuron