Spines slow down dendritic chloride diffusion and affect short-term ionic plasticity of GABAergic inhibition.
Sci Rep. 2016-03-18; 6(1):
DOI: 10.1038/srep23196
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1. Sci Rep. 2016 Mar 18;6:23196. doi: 10.1038/srep23196.
Spines slow down dendritic chloride diffusion and affect short-term ionic
plasticity of GABAergic inhibition.
Mohapatra N(1), Tønnesen J(2)(3), Vlachos A(1), Kuner T(4), Deller T(1), Nägerl
UV(2)(3), Santamaria F(5), Jedlicka P(1).
Author information:
(1)Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University
Frankfurt, Frankfurt/Main, Germany.
(2)Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.
(3)Interdisciplinary Institute for Neuroscience, University of Bordeaux, France.
(4)Institute of Anatomy and Cell Biology, Heidelberg University, Heidelberg,
Germany.
(5)Biology Department and Neurosciences Institute, The University of Texas at San
Antonio, San Antonio, USA.
Cl(-) plays a crucial role in neuronal function and synaptic inhibition. However,
the impact of neuronal morphology on the diffusion and redistribution of
intracellular Cl(-) is not well understood. The role of spines in Cl(-) diffusion
along dendritic trees has not been addressed so far. Because measuring fast and
spatially restricted Cl(-) changes within dendrites is not yet technically
possible, we used computational approaches to predict the effects of spines on
Cl(-) dynamics in morphologically complex dendrites. In all morphologies tested,
including dendrites imaged by super-resolution STED microscopy in live brain
tissue, spines slowed down longitudinal Cl(-) diffusion along dendrites. This
effect was robust and could be observed in both deterministic as well as
stochastic simulations. Cl(-) extrusion altered Cl(-) diffusion to a much lesser
extent than the presence of spines. The spine-dependent slowing of Cl(-)
diffusion affected the amount and spatial spread of changes in the GABA reversal
potential thereby altering homosynaptic as well as heterosynaptic short-term
ionic plasticity at GABAergic synapses in dendrites. Altogether, our results
suggest a fundamental role of dendritic spines in shaping Cl(-) diffusion, which
could be of relevance in the context of pathological conditions where spine
densities and neural excitability are perturbed.
DOI: 10.1038/srep23196
PMCID: PMC4796789
PMID: 26987404 [Indexed for MEDLINE]