Thickness controls spatial cooperation of calcium-activated dynamics in neuronal dendrite system

Norihiro Katayama, Mitsuyuki Nakao, Yoshinari Mizutani, Mitsuaki Yamamoto

Research output: Contribution to journalArticlepeer-review

Abstract

So far, neuronal dendrites have been characterized as electrically passive cables. However, recent physiological findings have revealed complex dynamics due to active conductances distributed over dendrites. In particular, the voltage-gated calcium and calcium-activated conductances are essential for producing diverse neuronal dynamics and synaptic plasticity. In this paper, we investigate the functional significance of the dendritic calcium-activated dynamics by computer simulations. First, the dendritic calcium-activated responses are modeled in a discrete compartmental form based on the physiological findings. Second, the basic stimulus-response characteristics of the single compartment dendrite model are investigated. The model is shown to reproduce the neuronal responses qualitatively. Third, the spatio-temporal dynamics of the dendrite shafts are modeled by longitudinally connecting 10 single compartments with coupling constants which are responsible for the dendrite thickness. The thick dendrite models, corresponding to proximal dendrites, respond in a spatially cooperative manner to a localized constant or periodic current stimulation. In contrast, the highly activated compartments are forced to be localized in the neighborhood of the stimulation-site in the fine dendrite models corresponding to distal dendrites. These results suggest that dendritic activities are spatially cooperated in a site-dependent manner. Since the synaptic inputs are known to be separately located responsible for the their originating neural systems, the site-dependent spatial cooperation suggested above could underlie the dendritic information processing specific to the neural systems which deliver their output to the neuron.

Original languageEnglish
Pages (from-to)197-205
Number of pages9
JournalIEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences
VolumeE80-A
Issue number1
Publication statusPublished - 1997 Jan 1

Keywords

  • Calcium spike
  • Compartment model
  • Intracellular calcium
  • Neuronal dendrite
  • Synaptic plasticity

ASJC Scopus subject areas

  • Signal Processing
  • Computer Graphics and Computer-Aided Design
  • Electrical and Electronic Engineering
  • Applied Mathematics

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