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A brief exposure to toluene vapor alters the intrinsic excitability of D2 medium spiny neurons in the rat ventral striatum

Although volatile organic solvents such as toluene are used for commercial and industrial uses, they are often voluntarily inhaled for their intoxicating and euphoric effects. Research into the effects of inhalants such as toluene on brain function have revealed actions on a variety of ligand-gated...

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Autores principales: Okas, Michael, Kastner, Abigail, Gioia, Dominic, Woodward, John J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10434816/
https://www.ncbi.nlm.nih.gov/pubmed/37600018
http://dx.doi.org/10.3389/fnins.2023.1235866
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author Okas, Michael
Kastner, Abigail
Gioia, Dominic
Woodward, John J.
author_facet Okas, Michael
Kastner, Abigail
Gioia, Dominic
Woodward, John J.
author_sort Okas, Michael
collection PubMed
description Although volatile organic solvents such as toluene are used for commercial and industrial uses, they are often voluntarily inhaled for their intoxicating and euphoric effects. Research into the effects of inhalants such as toluene on brain function have revealed actions on a variety of ligand-gated and voltage-activated ion channels involved in regulating neuronal excitability. Previous work from this laboratory has also shown that brief exposures to toluene vapor induce changes in the intrinsic excitability and synaptic transmission of neurons within the medial prefrontal cortex and ventral tegmental area that vary depending on projection target. In the present study, we recorded current-evoked spiking of medium spiny neurons (MSNs) in the nucleus accumbens (NAc) core and shell in adolescent rats exposed to an intoxicating concentration of toluene vapor. Compared to air controls, firing of NAc core MSNs in Sprague–Dawley rats was not altered 24 h after exposure to 10,500 ppm toluene vapor while spiking of NAc shell MSNs was enhanced at low current steps but reduced at higher current steps. When the rheobase current was used to putatively identify MSN subtypes, both “D1-like” and “D2-like” MSNs within the NAc shell but not core showed toluene-induced changes in firing. As toluene may itself have altered the rheobase resulting in misclassification of neuron subtype, we conducted additional studies using adolescent D2-Cre rats infused with a Cre-dependent mCherry reporter virus. Following toluene vapor exposure, spiking of NAc shell D2+ MSNs was enhanced at low current steps but inhibited at higher currents as compared to air controls while there were no differences in the firing of NAc shell D2- MSNs. The toluene-induced change in NAc D2+ shell MSN firing was accompanied by alterations in membrane resistance, rheobase, action potential rise time and height with no changes noted in D2- MSNs. Overall, these data add to a growing literature showing that brief exposures to intoxicating concentrations of toluene vapor causes selective alterations in the excitability of neurons within the addiction neurocircuitry that vary depending on sub-region, cell-type and projection target.
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spelling pubmed-104348162023-08-18 A brief exposure to toluene vapor alters the intrinsic excitability of D2 medium spiny neurons in the rat ventral striatum Okas, Michael Kastner, Abigail Gioia, Dominic Woodward, John J. Front Neurosci Neuroscience Although volatile organic solvents such as toluene are used for commercial and industrial uses, they are often voluntarily inhaled for their intoxicating and euphoric effects. Research into the effects of inhalants such as toluene on brain function have revealed actions on a variety of ligand-gated and voltage-activated ion channels involved in regulating neuronal excitability. Previous work from this laboratory has also shown that brief exposures to toluene vapor induce changes in the intrinsic excitability and synaptic transmission of neurons within the medial prefrontal cortex and ventral tegmental area that vary depending on projection target. In the present study, we recorded current-evoked spiking of medium spiny neurons (MSNs) in the nucleus accumbens (NAc) core and shell in adolescent rats exposed to an intoxicating concentration of toluene vapor. Compared to air controls, firing of NAc core MSNs in Sprague–Dawley rats was not altered 24 h after exposure to 10,500 ppm toluene vapor while spiking of NAc shell MSNs was enhanced at low current steps but reduced at higher current steps. When the rheobase current was used to putatively identify MSN subtypes, both “D1-like” and “D2-like” MSNs within the NAc shell but not core showed toluene-induced changes in firing. As toluene may itself have altered the rheobase resulting in misclassification of neuron subtype, we conducted additional studies using adolescent D2-Cre rats infused with a Cre-dependent mCherry reporter virus. Following toluene vapor exposure, spiking of NAc shell D2+ MSNs was enhanced at low current steps but inhibited at higher currents as compared to air controls while there were no differences in the firing of NAc shell D2- MSNs. The toluene-induced change in NAc D2+ shell MSN firing was accompanied by alterations in membrane resistance, rheobase, action potential rise time and height with no changes noted in D2- MSNs. Overall, these data add to a growing literature showing that brief exposures to intoxicating concentrations of toluene vapor causes selective alterations in the excitability of neurons within the addiction neurocircuitry that vary depending on sub-region, cell-type and projection target. Frontiers Media S.A. 2023-08-03 /pmc/articles/PMC10434816/ /pubmed/37600018 http://dx.doi.org/10.3389/fnins.2023.1235866 Text en Copyright © 2023 Okas, Kastner, Gioia and Woodward. https://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) and the copyright owner(s) 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
Okas, Michael
Kastner, Abigail
Gioia, Dominic
Woodward, John J.
A brief exposure to toluene vapor alters the intrinsic excitability of D2 medium spiny neurons in the rat ventral striatum
title A brief exposure to toluene vapor alters the intrinsic excitability of D2 medium spiny neurons in the rat ventral striatum
title_full A brief exposure to toluene vapor alters the intrinsic excitability of D2 medium spiny neurons in the rat ventral striatum
title_fullStr A brief exposure to toluene vapor alters the intrinsic excitability of D2 medium spiny neurons in the rat ventral striatum
title_full_unstemmed A brief exposure to toluene vapor alters the intrinsic excitability of D2 medium spiny neurons in the rat ventral striatum
title_short A brief exposure to toluene vapor alters the intrinsic excitability of D2 medium spiny neurons in the rat ventral striatum
title_sort brief exposure to toluene vapor alters the intrinsic excitability of d2 medium spiny neurons in the rat ventral striatum
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10434816/
https://www.ncbi.nlm.nih.gov/pubmed/37600018
http://dx.doi.org/10.3389/fnins.2023.1235866
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