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Circadian Modulation of the Cl(−) Equilibrium Potential in the Rat Suprachiasmatic Nuclei

The suprachiasmatic nuclei (SCN) constitute a circadian clock in mammals, where γ-amino-butyric acid (GABA) neurotransmission prevails and participates in different aspects of circadian regulation. Evidence suggests that GABA has an excitatory function in the SCN in addition to its typical inhibitor...

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Autores principales: Alamilla, Javier, Perez-Burgos, Azucena, Quinto, Daniel, Aguilar-Roblero, Raúl
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Hindawi Publishing Corporation 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4052495/
https://www.ncbi.nlm.nih.gov/pubmed/24949446
http://dx.doi.org/10.1155/2014/424982
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author Alamilla, Javier
Perez-Burgos, Azucena
Quinto, Daniel
Aguilar-Roblero, Raúl
author_facet Alamilla, Javier
Perez-Burgos, Azucena
Quinto, Daniel
Aguilar-Roblero, Raúl
author_sort Alamilla, Javier
collection PubMed
description The suprachiasmatic nuclei (SCN) constitute a circadian clock in mammals, where γ-amino-butyric acid (GABA) neurotransmission prevails and participates in different aspects of circadian regulation. Evidence suggests that GABA has an excitatory function in the SCN in addition to its typical inhibitory role. To examine this possibility further, we determined the equilibrium potential of GABAergic postsynaptic currents (E (GABA)) at different times of the day and in different regions of the SCN, using either perforated or whole cell patch clamp. Our results indicate that during the day most neurons in the dorsal SCN have an E (GABA) close to −30 mV while in the ventral SCN they have an E (GABA) close to −60 mV; this difference reverses during the night, in the dorsal SCN neurons have an E (GABA) of −60 mV and in the ventral SCN they have an E (GABA) of −30 mV. The depolarized equilibrium potential can be attributed to the activity of the Na(+)-K(+)-2Cl(−) (NKCC) cotransporter since the equilibrium potential becomes more negative following addition of the NKCC blocker bumetanide. Our results suggest an excitatory role for GABA in the SCN and further indicate both time (day versus night) and regional (dorsal versus ventral) modulation of E (GABA) in the SCN.
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spelling pubmed-40524952014-06-19 Circadian Modulation of the Cl(−) Equilibrium Potential in the Rat Suprachiasmatic Nuclei Alamilla, Javier Perez-Burgos, Azucena Quinto, Daniel Aguilar-Roblero, Raúl Biomed Res Int Research Article The suprachiasmatic nuclei (SCN) constitute a circadian clock in mammals, where γ-amino-butyric acid (GABA) neurotransmission prevails and participates in different aspects of circadian regulation. Evidence suggests that GABA has an excitatory function in the SCN in addition to its typical inhibitory role. To examine this possibility further, we determined the equilibrium potential of GABAergic postsynaptic currents (E (GABA)) at different times of the day and in different regions of the SCN, using either perforated or whole cell patch clamp. Our results indicate that during the day most neurons in the dorsal SCN have an E (GABA) close to −30 mV while in the ventral SCN they have an E (GABA) close to −60 mV; this difference reverses during the night, in the dorsal SCN neurons have an E (GABA) of −60 mV and in the ventral SCN they have an E (GABA) of −30 mV. The depolarized equilibrium potential can be attributed to the activity of the Na(+)-K(+)-2Cl(−) (NKCC) cotransporter since the equilibrium potential becomes more negative following addition of the NKCC blocker bumetanide. Our results suggest an excitatory role for GABA in the SCN and further indicate both time (day versus night) and regional (dorsal versus ventral) modulation of E (GABA) in the SCN. Hindawi Publishing Corporation 2014 2014-05-18 /pmc/articles/PMC4052495/ /pubmed/24949446 http://dx.doi.org/10.1155/2014/424982 Text en Copyright © 2014 Javier Alamilla et al. https://creativecommons.org/licenses/by/3.0/ This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Alamilla, Javier
Perez-Burgos, Azucena
Quinto, Daniel
Aguilar-Roblero, Raúl
Circadian Modulation of the Cl(−) Equilibrium Potential in the Rat Suprachiasmatic Nuclei
title Circadian Modulation of the Cl(−) Equilibrium Potential in the Rat Suprachiasmatic Nuclei
title_full Circadian Modulation of the Cl(−) Equilibrium Potential in the Rat Suprachiasmatic Nuclei
title_fullStr Circadian Modulation of the Cl(−) Equilibrium Potential in the Rat Suprachiasmatic Nuclei
title_full_unstemmed Circadian Modulation of the Cl(−) Equilibrium Potential in the Rat Suprachiasmatic Nuclei
title_short Circadian Modulation of the Cl(−) Equilibrium Potential in the Rat Suprachiasmatic Nuclei
title_sort circadian modulation of the cl(−) equilibrium potential in the rat suprachiasmatic nuclei
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4052495/
https://www.ncbi.nlm.nih.gov/pubmed/24949446
http://dx.doi.org/10.1155/2014/424982
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