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Stochastic and deterministic dynamics of intrinsically irregular firing in cortical inhibitory interneurons

Published version
Peer-reviewed

Type

Article

Change log

Authors

Mendonca, PR 
Vargas-Caballero, M 
Erdélyi, F 
Szabó, G 

Abstract

Most cortical neurons fire regularly when excited by a constant stimulus. In contrast, irregular-spiking (IS) interneurons are remarkable for the intrinsic variability of their spike timing, which can synchronize amongst IS cells via specific gap junctions. Here, we have studied the biophysical mechanisms of this irregular spiking in mice, and how IS cells fire in the context of synchronous network oscillations. Using patch-clamp recordings, artificial dynamic conductance injection, pharmacological analysis and computational modeling, we show that spike time irregularity is generated by a nonlinear dynamical interaction of voltage-dependent sodium and fast-inactivating potassium channels just below spike threshold, amplifying channel noise. This active irregularity may help IS cells synchronize with each other at gamma range frequencies, while resisting synchronization to lower input frequencies.

Description

Keywords

computational biology, cortical interneuron, mouse, neuroscience, spiking irregularity, systems biology, voltage-gated potassium conductance

Journal Title

eLife

Conference Name

Journal ISSN

2050-084X
2050-084X

Volume Title

5

Publisher

eLife
Sponsorship
Biotechnology and Biological Sciences Research Council, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Cambridge Overseas Trust