- Poster presentation
- Open Access
Modeling the effects of neuronal morphology on dendritic chloride diffusion and GABAergic inhibition
© Mohapatra et al; licensee BioMed Central Ltd. 2014
- Published: 21 July 2014
- Spine Density
- Neuronal Membrane
- Inhibitory Neurotransmission
- Dendritic Morphology
- Neuronal Morphology
Gamma-aminobutyric acid receptors (GABAARs) are ligand-gated chloride (Cl−) channels which mediate the majority of inhibitory neurotransmission in the CNS. Spatiotemporal changes of intracellular Cl− concentration alter the concentration gradient for Cl− across the neuronal membrane and thus affect the current flow through GABAARs and the efficacy of GABAergic inhibition. However, the impact of complex neuronal morphology on Cl− diffusion and the redistribution of intracellular Cl− is not well understood. Recently, computational models for Cl− diffusion and GABAAR-mediated inhibition in realistic neuronal morphologies became available [1–3]. Here we have used computational models of morphologically complex dendrites to test the effects of spines on Cl− diffusion. In all dendritic morphologies tested, spines slowed down longitudinal Cl− diffusion along dendrites and decreased the amount and spatial spread of synaptically evoked Cl− changes. Spine densities of 2-10 spines/µm decreased the longitudinal diffusion coefficient of Cl− to 80-30% of its value in smooth dendrites, respectively. These results suggest that spines are able to limit short-term ionic plasticity  at dendritic GABAergic synapses.
Supported by the NSF/BMBF (US-German Collaboration in Computational Neuroscience, No. 01GQ1203A).
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