title: Gap junctions compensate for sublinear dendritic integration in an inhibitory network.
abstract: Electrically coupled inhibitory interneurons dynamically control network excitability, yet little is known about how chemical and electrical synapses regulate their activity. Using two-photon glutamate uncaging and dendritic patch-clamp recordings, we found that the dendrites of cerebellar Golgi interneurons acted as passive cables. They conferred distance-dependent sublinear synaptic integration and weakened distal excitatory inputs. Gap junctions were present at a higher density on distal dendrites and contributed substantially to membrane conductance. Depolarization of one Golgi cell increased firing in its neighbors, and inclusion of dendritic gap junctions in interneuron network models enabled distal excitatory synapses to drive network activity more effectively. Our results suggest that dendritic gap junctions counteract sublinear dendritic integration by enabling excitatory synaptic charge to spread into the dendrites of neighboring inhibitory interneurons.
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
authors.forename: Koen
authors.initials: K
authors.lastname: Vervaeke
authors.forename: Andrea
authors.initials: A
authors.lastname: Lorincz
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Nusser
authors.forename: R Angus
authors.initials: RA
authors.lastname: Silver
mesh_terms: D000200:Action Potentials; D000818:Animals; D001369:Axons / Q000502:physiology; D002525:Cerebellar Cortex / Q000166:cytology; D003198:Computer Simulation; D003712:Dendrites / Q000502:physiology* / Q000648:ultrastructure*; D054351:Electrical Synapses / Q000502:physiology* / Q000648:ultrastructure; D019706:Excitatory Postsynaptic Potentials; D007395:Interneurons / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology* / Q000648:ultrastructure; D009433:Neural Inhibition; D018408:Patch-Clamp Techniques; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission
chemical_list: D007473:Ion Channels