title: Strength and duration of perisomatic GABAergic inhibition depend on distance between synaptically connected cells.
abstract: GABAergic perisoma-inhibiting fast-spiking interneurons (PIIs) effectively control the activity of large neuron populations by their wide axonal arborizations. It is generally assumed that the output of one PII to its target cells is strong and rapid. Here, we show that, unexpectedly, both strength and time course of PII-mediated perisomatic inhibition change with distance between synaptically connected partners in the rodent hippocampus. Synaptic signals become weaker due to lower contact numbers and decay more slowly with distance, very likely resulting from changes in GABAA receptor subunit composition. When distance-dependent synaptic inhibition is introduced to a rhythmically active neuronal network model, randomly driven principal cell assemblies are strongly synchronized by the PIIs, leading to higher precision in principal cell spike times than in a network with uniform synaptic inhibition.
authors.affiliation: Physiologisches Institut I and Spemann Graduate School of Biology and Medicine, and Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany; Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; and.
authors.forename: Michael
authors.initials: M
authors.lastname: Strüber
authors.affiliation: Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Jonas
authors.affiliation: Physiologisches Institut I and Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; and bartos@physiologie.uni-freiburg.de.
authors.forename: Marlene
authors.initials: M
authors.lastname: Bartos
mesh_terms: D000818:Animals; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D009415:Nerve Net / Q000166:cytology / Q000378:metabolism*; D009433:Neural Inhibition / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology*
keywords: basket cell; dentate gyrus; gamma oscillations; interneurons; synaptic transmission