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Modeling the effects of neuronal morphology on dendritic chloride diffusion and GABAergic inhibition
BMC Neuroscience volume 15, Article number: P138 (2014)
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.
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Supported by the NSF/BMBF (US-German Collaboration in Computational Neuroscience, No. 01GQ1203A).
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Mohapatra, N., Santamaria, F. & Jedlicka, P. Modeling the effects of neuronal morphology on dendritic chloride diffusion and GABAergic inhibition. BMC Neurosci 15, P138 (2014) doi:10.1186/1471-2202-15-S1-P138
- Spine Density
- Neuronal Membrane
- Inhibitory Neurotransmission
- Dendritic Morphology
- Neuronal Morphology