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Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons
Cortical fast-spiking (FS) interneurons display highly variable electrophysiological properties. Their spike responses to step currents occur almost immediately following the step onset or after a substantial delay, during which subthreshold oscillations are frequently observed. Their firing pattern...
Autores principales: | , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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Public Library of Science
2007
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1941757/ https://www.ncbi.nlm.nih.gov/pubmed/17696606 http://dx.doi.org/10.1371/journal.pcbi.0030156 |
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author | Golomb, David Donner, Karnit Shacham, Liron Shlosberg, Dan Amitai, Yael Hansel, David |
author_facet | Golomb, David Donner, Karnit Shacham, Liron Shlosberg, Dan Amitai, Yael Hansel, David |
author_sort | Golomb, David |
collection | PubMed |
description | Cortical fast-spiking (FS) interneurons display highly variable electrophysiological properties. Their spike responses to step currents occur almost immediately following the step onset or after a substantial delay, during which subthreshold oscillations are frequently observed. Their firing patterns include high-frequency tonic firing and rhythmic or irregular bursting (stuttering). What is the origin of this variability? In the present paper, we hypothesize that it emerges naturally if one assumes a continuous distribution of properties in a small set of active channels. To test this hypothesis, we construct a minimal, single-compartment conductance-based model of FS cells that includes transient Na(+), delayed-rectifier K(+), and slowly inactivating d-type K(+) conductances. The model is analyzed using nonlinear dynamical system theory. For small Na(+) window current, the neuron exhibits high-frequency tonic firing. At current threshold, the spike response is almost instantaneous for small d-current conductance, g (d), and it is delayed for larger g (d). As g (d) further increases, the neuron stutters. Noise substantially reduces the delay duration and induces subthreshold oscillations. In contrast, when the Na(+) window current is large, the neuron always fires tonically. Near threshold, the firing rates are low, and the delay to firing is only weakly sensitive to noise; subthreshold oscillations are not observed. We propose that the variability in the response of cortical FS neurons is a consequence of heterogeneities in their g (d) and in the strength of their Na(+) window current. We predict the existence of two types of firing patterns in FS neurons, differing in the sensitivity of the delay duration to noise, in the minimal firing rate of the tonic discharge, and in the existence of subthreshold oscillations. We report experimental results from intracellular recordings supporting this prediction. |
format | Text |
id | pubmed-1941757 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2007 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-19417572007-09-07 Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons Golomb, David Donner, Karnit Shacham, Liron Shlosberg, Dan Amitai, Yael Hansel, David PLoS Comput Biol Research Article Cortical fast-spiking (FS) interneurons display highly variable electrophysiological properties. Their spike responses to step currents occur almost immediately following the step onset or after a substantial delay, during which subthreshold oscillations are frequently observed. Their firing patterns include high-frequency tonic firing and rhythmic or irregular bursting (stuttering). What is the origin of this variability? In the present paper, we hypothesize that it emerges naturally if one assumes a continuous distribution of properties in a small set of active channels. To test this hypothesis, we construct a minimal, single-compartment conductance-based model of FS cells that includes transient Na(+), delayed-rectifier K(+), and slowly inactivating d-type K(+) conductances. The model is analyzed using nonlinear dynamical system theory. For small Na(+) window current, the neuron exhibits high-frequency tonic firing. At current threshold, the spike response is almost instantaneous for small d-current conductance, g (d), and it is delayed for larger g (d). As g (d) further increases, the neuron stutters. Noise substantially reduces the delay duration and induces subthreshold oscillations. In contrast, when the Na(+) window current is large, the neuron always fires tonically. Near threshold, the firing rates are low, and the delay to firing is only weakly sensitive to noise; subthreshold oscillations are not observed. We propose that the variability in the response of cortical FS neurons is a consequence of heterogeneities in their g (d) and in the strength of their Na(+) window current. We predict the existence of two types of firing patterns in FS neurons, differing in the sensitivity of the delay duration to noise, in the minimal firing rate of the tonic discharge, and in the existence of subthreshold oscillations. We report experimental results from intracellular recordings supporting this prediction. Public Library of Science 2007-08 2007-08-10 /pmc/articles/PMC1941757/ /pubmed/17696606 http://dx.doi.org/10.1371/journal.pcbi.0030156 Text en © 2007 Golomb et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Golomb, David Donner, Karnit Shacham, Liron Shlosberg, Dan Amitai, Yael Hansel, David Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons |
title | Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons |
title_full | Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons |
title_fullStr | Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons |
title_full_unstemmed | Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons |
title_short | Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons |
title_sort | mechanisms of firing patterns in fast-spiking cortical interneurons |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1941757/ https://www.ncbi.nlm.nih.gov/pubmed/17696606 http://dx.doi.org/10.1371/journal.pcbi.0030156 |
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