Detailed Information

Cited 0 time in webofscience Cited 0 time in scopus
Metadata Downloads

Synaptic calcium regulation in hair cells of the chicken basilar papilla

Authors
Im, G.J.Moskowitz, H.S.Lehar, M.Hiel, H.Fuchs, P.A.
Issue Date
2014
Publisher
Society for Neuroscience
Keywords
Acetylcholine; Calcium store; Cochlea; Efferent inhibition; Hair cell; Synaptic cistern
Citation
Journal of Neuroscience, v.34, no.50, pp.16688 - 16697
Indexed
SCIE
SCOPUS
Journal Title
Journal of Neuroscience
Volume
34
Number
50
Start Page
16688
End Page
16697
URI
https://scholar.korea.ac.kr/handle/2021.sw.korea/100802
DOI
10.1523/JNEUROSCI.2615-14.2014
ISSN
0270-6474
Abstract
Cholinergic inhibition of hair cells occurs by activation of calcium-dependent potassium channels. A near-membrane postsynaptic cistern has been proposed to serve as a store from which calcium is released to supplement influx through the ionotropic ACh receptor. However, the time and voltage dependence of acetylcholine (ACh)-evoked potassium currents reveal a more complex relationship between calcium entry and release from stores. The present work uses voltage steps to regulate calcium influx during the application of ACh to hair cells in the chicken basilar papilla. When calcium influx was terminated at positive membrane potential, the ACh-evoked potassium current decayed exponentially over ~100 ms. However, at negative membrane potentials, this current exhibited a secondary rise in amplitude that could be eliminated by dihydropyridine block of the voltage-gated calcium channels of the hair cell. Calcium entering through voltage-gated channels may transit through the postsynaptic cistern, since ryanodine and sarcoendoplasmic reticulum calcium-ATPase blockers altered the time course and magnitude of this secondary, voltage-dependent contribution to ACh-evoked potassium current. Serial section electron microscopy showed that efferent and afferent synaptic structures are juxtaposed, supporting the possibility that voltage-gated influx at afferent ribbon synapses influences calcium homeostasis during long-lasting cholinergic inhibition. In contrast, spontaneous postsynaptic currents (“minis”) resulting from stochastic efferent release of ACh were made briefer by ryanodine, supporting the hypothesis that the synaptic cistern serves primarily as a calcium barrier and sink during low-level synaptic activity. Hypolemmal cisterns such as that at the efferent synapse of the hair cell can play a dynamic role in segregating near-membrane calcium for short-term and long-term signaling. © 2014 the authors.
Files in This Item
There are no files associated with this item.
Appears in
Collections
College of Medicine > Department of Medical Science > 1. Journal Articles

qrcode

Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.

Related Researcher

Researcher Im, Gi Jung photo

Im, Gi Jung
의과대학 (의학과)
Read more

Altmetrics

Total Views & Downloads

BROWSE