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Effects of GABA(B) receptor activation on excitability of IB4-positive maxillary trigeminal ganglion neurons: Possible involvement of TREK2 activation
IB4-positive maxillary trigeminal ganglion (TG) neurons are a subtype of afferent neurons involving nociception in orofacial regions, and excitability of these neurons is associated with orofacial nociceptive sensitivity. TREK-2 channel is a member of two-pore domain potassium (K2P) channel family m...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
SAGE Publications
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8411610/ https://www.ncbi.nlm.nih.gov/pubmed/34461754 http://dx.doi.org/10.1177/17448069211042963 |
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author | Chang, Ya-Ting Ling, Jennifer Gu, Jianguo G |
author_facet | Chang, Ya-Ting Ling, Jennifer Gu, Jianguo G |
author_sort | Chang, Ya-Ting |
collection | PubMed |
description | IB4-positive maxillary trigeminal ganglion (TG) neurons are a subtype of afferent neurons involving nociception in orofacial regions, and excitability of these neurons is associated with orofacial nociceptive sensitivity. TREK-2 channel is a member of two-pore domain potassium (K2P) channel family mediating leak K(+) currents. It has been shown previously that TREK-2 channel activity can be enhanced following GABAB receptor activation, leading to a reduction of cortical neuron excitability. In the present study, we have characterized TREK-2 channel expression on maxillary TG neurons and investigated the effect of the GABAB agonist baclofen on electrophysiological properties of small-sized maxillary TG neurons of rats. We show with immunohistochemistry that TREK-2 channels are predominantly expressed in small-sized IB4-positive maxillary TG neurons. Patch-clamp recordings on neurons in ex vivo TG preparations show that baclofen hyperpolarizes resting membrane potentials, increases outward leak currents, and decreases input resistances in IB4-positive maxillary TG neurons. Moreover, baclofen significantly reduces action potential (AP) firing in IB4-positive maxillary TG neurons. In contrast, baclofen shows no significant effect on electrophysiological properties of small-sized nociceptive-like and non-nociceptive-like maxillary trigeminal neurons that are IB4-negatve. Our results suggest that TREK-2 channel activity can be enhanced by baclofen, leading to reduced excitability of IB4-positive maxillary TG neurons. This finding provides new insights into the role of TREK-2 and GABAB receptors in controlling nociceptive sensitivity in orofacial regions, which may have therapeutic implications. |
format | Online Article Text |
id | pubmed-8411610 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | SAGE Publications |
record_format | MEDLINE/PubMed |
spelling | pubmed-84116102021-09-03 Effects of GABA(B) receptor activation on excitability of IB4-positive maxillary trigeminal ganglion neurons: Possible involvement of TREK2 activation Chang, Ya-Ting Ling, Jennifer Gu, Jianguo G Mol Pain Research Article IB4-positive maxillary trigeminal ganglion (TG) neurons are a subtype of afferent neurons involving nociception in orofacial regions, and excitability of these neurons is associated with orofacial nociceptive sensitivity. TREK-2 channel is a member of two-pore domain potassium (K2P) channel family mediating leak K(+) currents. It has been shown previously that TREK-2 channel activity can be enhanced following GABAB receptor activation, leading to a reduction of cortical neuron excitability. In the present study, we have characterized TREK-2 channel expression on maxillary TG neurons and investigated the effect of the GABAB agonist baclofen on electrophysiological properties of small-sized maxillary TG neurons of rats. We show with immunohistochemistry that TREK-2 channels are predominantly expressed in small-sized IB4-positive maxillary TG neurons. Patch-clamp recordings on neurons in ex vivo TG preparations show that baclofen hyperpolarizes resting membrane potentials, increases outward leak currents, and decreases input resistances in IB4-positive maxillary TG neurons. Moreover, baclofen significantly reduces action potential (AP) firing in IB4-positive maxillary TG neurons. In contrast, baclofen shows no significant effect on electrophysiological properties of small-sized nociceptive-like and non-nociceptive-like maxillary trigeminal neurons that are IB4-negatve. Our results suggest that TREK-2 channel activity can be enhanced by baclofen, leading to reduced excitability of IB4-positive maxillary TG neurons. This finding provides new insights into the role of TREK-2 and GABAB receptors in controlling nociceptive sensitivity in orofacial regions, which may have therapeutic implications. SAGE Publications 2021-08-30 /pmc/articles/PMC8411610/ /pubmed/34461754 http://dx.doi.org/10.1177/17448069211042963 Text en © The Author(s) 2021 https://creativecommons.org/licenses/by-nc/4.0/Creative Commons Non Commercial CC BY-NC: This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage). |
spellingShingle | Research Article Chang, Ya-Ting Ling, Jennifer Gu, Jianguo G Effects of GABA(B) receptor activation on excitability of IB4-positive maxillary trigeminal ganglion neurons: Possible involvement of TREK2 activation |
title | Effects of GABA(B) receptor activation on excitability of
IB4-positive maxillary trigeminal ganglion neurons: Possible involvement of
TREK2 activation |
title_full | Effects of GABA(B) receptor activation on excitability of
IB4-positive maxillary trigeminal ganglion neurons: Possible involvement of
TREK2 activation |
title_fullStr | Effects of GABA(B) receptor activation on excitability of
IB4-positive maxillary trigeminal ganglion neurons: Possible involvement of
TREK2 activation |
title_full_unstemmed | Effects of GABA(B) receptor activation on excitability of
IB4-positive maxillary trigeminal ganglion neurons: Possible involvement of
TREK2 activation |
title_short | Effects of GABA(B) receptor activation on excitability of
IB4-positive maxillary trigeminal ganglion neurons: Possible involvement of
TREK2 activation |
title_sort | effects of gaba(b) receptor activation on excitability of
ib4-positive maxillary trigeminal ganglion neurons: possible involvement of
trek2 activation |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8411610/ https://www.ncbi.nlm.nih.gov/pubmed/34461754 http://dx.doi.org/10.1177/17448069211042963 |
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