Ion channel density and threshold dynamics of repetitive firing in a cortical neuron model
2007 (English)In: Biosystems (Amsterdam. Print), ISSN 0303-2647, E-ISSN 1872-8324, Vol. 89, no 1-3, 117-125 p.Article in journal (Refereed) Published
Modifying the density and distribution of ion channels in a neuron (by natural up- and down-regulation, by pharmacological intervention or by spontaneous mutations) changes its activity pattern. In the present investigation, we analyze how the impulse patterns are regulated by the density of voltage-gated channels in a model neuron, based on voltage clamp measurements of hippocampal interneurons. At least three distinct oscillatory patterns, associated with three distinct regions in the Na-K channel density plane, were found. A stability analysis showed that the different regions are characterized by saddle-node, double-orbit, and Hopf bifurcation threshold dynamics, respectively. Single strongly graded action potentials occur in an area outside the oscillatory regions, but less graded action potentials occur together with repetitive firing over a considerable range of channel densities. The presently found relationship between channel densities and oscillatory behavior may be relevance for understanding principal spiking patterns of cortical neurons (regular firing and fast spiking). It may also be of relevance for understanding the action of pharmacological compounds on brain oscillatory activity.
Place, publisher, year, edition, pages
2007. Vol. 89, no 1-3, 117-125 p.
ion channels, Hopf bifurcation, saddle-node bifurcation, hippocampal interneuron, threshold dynamics
IdentifiersURN: urn:nbn:se:kth:diva-41098DOI: 10.1016/j.biosystems.2006.03.015ISI: 000247057900018PubMedID: 17287076ScopusID: 2-s2.0-34247566169OAI: oai:DiVA.org:kth-41098DiVA: diva2:443840
6th International Workshop on Neural Coding Location: Marburg, Germany, Date: AUG 23-28, 2005 2011-09-272011-09-232011-09-27Bibliographically approved