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Poster presentation | Open | Published:

Modeling the effects of neuronal morphology on dendritic chloride diffusion and GABAergic inhibition

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 [13]. 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 [4] at dendritic GABAergic synapses.

References

  1. 1.

    Jedlicka P, Deller T, Gutkin BS, Backus KH: Activity-dependent intracellular chloride accumulation and diffusion controls GABAA receptor-mediated synaptic transmission. Hippocampus. 2011, 21: 885-898.

  2. 2.

    Doyon N, Prescott SA, Castonguay A, Godin AG, Kröger H, Koninck YD: Efficacy of synaptic inhibition depends on multiple, dynamically interacting mechanisms implicated in chloride homeostasis. PLoS Comput Biol. 2011, 7 (9): e1002149-10.1371/journal.pcbi.1002149.

  3. 3.

    Lewin N, Aksay E, Clancy CE: Computational modeling reveals dendritic origins of GABAA-mediated excitation in CA1 pyramidal neurons. PLoS One. 2012, 7 (10): e47250-10.1371/journal.pone.0047250.

  4. 4.

    Raimondo JV, Markram H, Akerman CJ: Short-term ionic plasticity at GABAergic synapses. Front Syn Neurosci. 2012, 4: 5-10.3389/fnsyn.2012.00005.

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Acknowledgements

Supported by the NSF/BMBF (US-German Collaboration in Computational Neuroscience, No. 01GQ1203A).

Author information

Correspondence to Namrata Mohapatra.

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Keywords

  • Spine Density
  • Neuronal Membrane
  • Inhibitory Neurotransmission
  • Dendritic Morphology
  • Neuronal Morphology