Sub-quantal release is not dominant during prolonged depolarization in adrenal chromaffin cells

Exocytosis, which mediates important functions like synaptic transmission and stress responses, has been postulated to release all transmitter molecules in the vesicle in the “all-or-none” quantal hypothesis. Challenging this hypothesis, amperometric current recordings of catecholamine release propo...

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Main Authors: Lisi Wei, Xin Wang, Min Sun, Wonchul Shin, Kevin D. Gillis, Ling-Gang Wu
Format: Article
Language:English
Published: Elsevier 2025-06-01
Series:Biophysical Reports
Online Access:http://www.sciencedirect.com/science/article/pii/S2667074725000175
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author Lisi Wei
Xin Wang
Min Sun
Wonchul Shin
Kevin D. Gillis
Ling-Gang Wu
author_facet Lisi Wei
Xin Wang
Min Sun
Wonchul Shin
Kevin D. Gillis
Ling-Gang Wu
author_sort Lisi Wei
collection DOAJ
description Exocytosis, which mediates important functions like synaptic transmission and stress responses, has been postulated to release all transmitter molecules in the vesicle in the “all-or-none” quantal hypothesis. Challenging this hypothesis, amperometric current recordings of catecholamine release propose that sub-quantal or partial transmitter release is dominant in various cell types, particularly chromaffin cells. The sub-quantal hypothesis predicts that fusion pore closure (kiss-and-run fusion), the cause of sub-quantal release, is dominant, and blocking pore closure increases quantal size. We tested these predictions by imaging fusion pore closure and amperometric recording of catecholamine release in chromaffin cells during high potassium application, the most-used stimulation protocol for sub-quantal release study. We found that fusion pore closure is not predominant, and inhibition of the fusion pore closure does not increase the quantal size calculated from the amperometric current charge when a sufficiently long integration time is used. These results suggest that sub-quantal release is not prevalent during high potassium application in adrenal chromaffin cells.
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issn 2667-0747
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spelling doaj-art-33c4bb861d7d448ab7568169c0ffde202025-08-20T02:25:37ZengElsevierBiophysical Reports2667-07472025-06-015210021210.1016/j.bpr.2025.100212Sub-quantal release is not dominant during prolonged depolarization in adrenal chromaffin cellsLisi Wei0Xin Wang1Min Sun2Wonchul Shin3Kevin D. Gillis4Ling-Gang Wu5National Institute of Neurological Disorders and Stroke, 35 Convent Dr., Bldg. 35, Bethesda, MD 20892, USANational Institute of Neurological Disorders and Stroke, 35 Convent Dr., Bldg. 35, Bethesda, MD 20892, USANational Institute of Neurological Disorders and Stroke, 35 Convent Dr., Bldg. 35, Bethesda, MD 20892, USANational Institute of Neurological Disorders and Stroke, 35 Convent Dr., Bldg. 35, Bethesda, MD 20892, USADepartment of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO 65201, USANational Institute of Neurological Disorders and Stroke, 35 Convent Dr., Bldg. 35, Bethesda, MD 20892, USA; Corresponding authorExocytosis, which mediates important functions like synaptic transmission and stress responses, has been postulated to release all transmitter molecules in the vesicle in the “all-or-none” quantal hypothesis. Challenging this hypothesis, amperometric current recordings of catecholamine release propose that sub-quantal or partial transmitter release is dominant in various cell types, particularly chromaffin cells. The sub-quantal hypothesis predicts that fusion pore closure (kiss-and-run fusion), the cause of sub-quantal release, is dominant, and blocking pore closure increases quantal size. We tested these predictions by imaging fusion pore closure and amperometric recording of catecholamine release in chromaffin cells during high potassium application, the most-used stimulation protocol for sub-quantal release study. We found that fusion pore closure is not predominant, and inhibition of the fusion pore closure does not increase the quantal size calculated from the amperometric current charge when a sufficiently long integration time is used. These results suggest that sub-quantal release is not prevalent during high potassium application in adrenal chromaffin cells.http://www.sciencedirect.com/science/article/pii/S2667074725000175
spellingShingle Lisi Wei
Xin Wang
Min Sun
Wonchul Shin
Kevin D. Gillis
Ling-Gang Wu
Sub-quantal release is not dominant during prolonged depolarization in adrenal chromaffin cells
Biophysical Reports
title Sub-quantal release is not dominant during prolonged depolarization in adrenal chromaffin cells
title_full Sub-quantal release is not dominant during prolonged depolarization in adrenal chromaffin cells
title_fullStr Sub-quantal release is not dominant during prolonged depolarization in adrenal chromaffin cells
title_full_unstemmed Sub-quantal release is not dominant during prolonged depolarization in adrenal chromaffin cells
title_short Sub-quantal release is not dominant during prolonged depolarization in adrenal chromaffin cells
title_sort sub quantal release is not dominant during prolonged depolarization in adrenal chromaffin cells
url http://www.sciencedirect.com/science/article/pii/S2667074725000175
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AT xinwang subquantalreleaseisnotdominantduringprolongeddepolarizationinadrenalchromaffincells
AT minsun subquantalreleaseisnotdominantduringprolongeddepolarizationinadrenalchromaffincells
AT wonchulshin subquantalreleaseisnotdominantduringprolongeddepolarizationinadrenalchromaffincells
AT kevindgillis subquantalreleaseisnotdominantduringprolongeddepolarizationinadrenalchromaffincells
AT linggangwu subquantalreleaseisnotdominantduringprolongeddepolarizationinadrenalchromaffincells