A sodium background conductance controls the spiking pattern of mouse adrenal chromaffin cells in situ

Autor: Pierre Fontanaud, Philippe Lory, Stéphanie Ventéo, Nathalie C. Guérineau, Alexandre Milman, Arnaud Monteil, Jean-Louis Bossu
Přispěvatelé: Institut de Génomique Fonctionnelle (IGF), Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences de Montpellier - Déficits sensoriels et moteurs (INM), Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut des Neurosciences Cellulaires et Intégratives (INCI), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Fondation pour la Recherche Médicale, ANR-11-LABX-0015,ICST,Canaux ioniques d'intérêt thérapeutique(2011), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Guerineau, Nathalie C., Laboratoires d'excellence - Canaux ioniques d'intérêt thérapeutique - - ICST2011 - ANR-11-LABX-0015 - LABX - VALID, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences de Montpellier (INM)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
0301 basic medicine
Physiology
sodium leak channel NALCN
resting membrane potential
[SDV]Life Sciences [q-bio]
acute slice
Action Potentials
Mice
03 medical and health sciences
chemistry.chemical_compound
Bursting
0302 clinical medicine
excitability
medicine
Animals
[SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]
burst firing
chromaffin cells
Ions
Membrane potential
spiking pattern
adrenal gland
NALCN
Sodium
Depolarization
Membrane hyperpolarization
Resting potential
[SDV] Life Sciences [q-bio]
030104 developmental biology
medicine.anatomical_structure
chemistry
Adrenal Medulla
Chromaffin cell
Biophysics
Tetrodotoxin
sodium background conductance
[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]
Adrenal medulla
030217 neurology & neurosurgery
Perspectives
sodium channel
Zdroj: The Journal of Physiology
The Journal of Physiology, Wiley, 2021, 599 (6), pp.1855-1883. ⟨10.1113/jp281044⟩
The Journal of Physiology, 2021, 599 (6), pp.1855-1883. ⟨10.1113/jp281044⟩
ISSN: 0022-3751
1469-7793
DOI: 10.1113/jp281044⟩
Popis: Key points Mouse chromaffin cells in acute adrenal slices exhibit two distinct spiking patterns, a repetitive mode and a bursting mode. A sodium background conductance operates at rest as demonstrated by the membrane hyperpolarization evoked by a low Na+ -containing extracellular saline. This sodium background current is insensitive to TTX, is not blocked by Cs+ ions and displays a linear I-V relationship at potentials close to chromaffin cell resting potential. Its properties are reminiscent of those of the sodium leak channel NALCN. In the adrenal gland, Nalcn mRNA is selectively expressed in chromaffin cells. The study fosters our understanding of how the spiking pattern of chromaffin cells is regulated and adds a sodium background conductance to the list of players involved in the stimulus-secretion coupling of the adrenomedullary tissue. Abstract Chromaffin cells (CCs) are the master neuroendocrine units for the secretory function of the adrenal medulla and a finely-tuned regulation of their electrical activity is required for appropriate catecholamine secretion in response to the organismal demand. Here, we aim at deciphering how the spiking pattern of mouse CCs is regulated by the ion conductances operating near the resting membrane potential (RMP). At RMP, mouse CCs display a composite firing pattern, alternating between active periods composed of action potentials spiking with a regular or a bursting mode, and silent periods. RMP is sensitive to changes in extracellular sodium concentration, and a low Na+ -containing saline hyperpolarizes the membrane, regardless of the discharge pattern. This RMP drive reflects the contribution of a depolarizing conductance, which is (i) not blocked by tetrodotoxin or caesium, (ii) displays a linear I-V relationship between -110 and -40 mV, and (iii) is carried by cations with a conductance sequence gNa > gK > gCs . These biophysical attributes, together with the expression of the sodium-leak channel Nalcn transcript in CCs, state credible the contribution of NALCN. This inaugural report opens new research routes in the field of CC stimulus-secretion coupling, and extends the inventory of tissues in which NALCN is expressed to neuroendocrine glands.
Databáze: OpenAIRE
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