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Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons
Central neurons express a variety of neuronal types and ion channels that promote firing heterogeneity among their distinct neuronal populations. Action potential (AP) phasic firing, produced by low-threshold voltage-activated potassium currents (VAKCs), is commonly observed in mammalian brainstem n...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Media S.A.
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4674572/ https://www.ncbi.nlm.nih.gov/pubmed/26696830 http://dx.doi.org/10.3389/fncel.2015.00471 |
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author | Dagostin, André A. Lovell, Peter V. Hilscher, Markus M. Mello, Claudio V. Leão, Ricardo M. |
author_facet | Dagostin, André A. Lovell, Peter V. Hilscher, Markus M. Mello, Claudio V. Leão, Ricardo M. |
author_sort | Dagostin, André A. |
collection | PubMed |
description | Central neurons express a variety of neuronal types and ion channels that promote firing heterogeneity among their distinct neuronal populations. Action potential (AP) phasic firing, produced by low-threshold voltage-activated potassium currents (VAKCs), is commonly observed in mammalian brainstem neurons involved in the processing of temporal properties of the acoustic information. The avian caudomedial nidopallium (NCM) is an auditory area analogous to portions of the mammalian auditory cortex that is involved in the perceptual discrimination and memorization of birdsong and shows complex responses to auditory stimuli We performed in vitro whole-cell patch-clamp recordings in brain slices from adult zebra finches (Taeniopygia guttata) and observed that half of NCM neurons fire APs phasically in response to membrane depolarizations, while the rest fire transiently or tonically. Phasic neurons fired APs faster and with more temporal precision than tonic and transient neurons. These neurons had similar membrane resting potentials, but phasic neurons had lower membrane input resistance and time constant. Surprisingly phasic neurons did not express low-threshold VAKCs, which curtailed firing in phasic mammalian brainstem neurons, having similar VAKCs to other NCM neurons. The phasic firing was determined not by VAKCs, but by the potassium background leak conductances, which was more prominently expressed in phasic neurons, a result corroborated by pharmacological, dynamic-clamp, and modeling experiments. These results reveal a new role for leak currents in generating firing diversity in central neurons. |
format | Online Article Text |
id | pubmed-4674572 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-46745722015-12-22 Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons Dagostin, André A. Lovell, Peter V. Hilscher, Markus M. Mello, Claudio V. Leão, Ricardo M. Front Cell Neurosci Neuroscience Central neurons express a variety of neuronal types and ion channels that promote firing heterogeneity among their distinct neuronal populations. Action potential (AP) phasic firing, produced by low-threshold voltage-activated potassium currents (VAKCs), is commonly observed in mammalian brainstem neurons involved in the processing of temporal properties of the acoustic information. The avian caudomedial nidopallium (NCM) is an auditory area analogous to portions of the mammalian auditory cortex that is involved in the perceptual discrimination and memorization of birdsong and shows complex responses to auditory stimuli We performed in vitro whole-cell patch-clamp recordings in brain slices from adult zebra finches (Taeniopygia guttata) and observed that half of NCM neurons fire APs phasically in response to membrane depolarizations, while the rest fire transiently or tonically. Phasic neurons fired APs faster and with more temporal precision than tonic and transient neurons. These neurons had similar membrane resting potentials, but phasic neurons had lower membrane input resistance and time constant. Surprisingly phasic neurons did not express low-threshold VAKCs, which curtailed firing in phasic mammalian brainstem neurons, having similar VAKCs to other NCM neurons. The phasic firing was determined not by VAKCs, but by the potassium background leak conductances, which was more prominently expressed in phasic neurons, a result corroborated by pharmacological, dynamic-clamp, and modeling experiments. These results reveal a new role for leak currents in generating firing diversity in central neurons. Frontiers Media S.A. 2015-12-10 /pmc/articles/PMC4674572/ /pubmed/26696830 http://dx.doi.org/10.3389/fncel.2015.00471 Text en Copyright © 2015 Dagostin, Lovell, Hilscher, Mello and Leão . http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Neuroscience Dagostin, André A. Lovell, Peter V. Hilscher, Markus M. Mello, Claudio V. Leão, Ricardo M. Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons |
title | Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons |
title_full | Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons |
title_fullStr | Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons |
title_full_unstemmed | Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons |
title_short | Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons |
title_sort | control of phasic firing by a background leak current in avian forebrain auditory neurons |
topic | Neuroscience |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4674572/ https://www.ncbi.nlm.nih.gov/pubmed/26696830 http://dx.doi.org/10.3389/fncel.2015.00471 |
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