Journal article
All-or-None Ca2+ Release from Intracellular Stores Triggered by Ca2+ Influx through Voltage-Gated Ca2+ Channels in Rat Sensory Neurons
The Journal of neuroscience, Vol.17(19), pp.7404-7414
10/01/1997
DOI: 10.1523/JNEUROSCI.17-19-07404.1997
PMID: 9295386
Abstract
Ca
2+
-induced Ca
2+
release (CICR) from intracellular stores amplifies the Ca
2+
signal that results from depolarization. In neurons, the amplification has been described as a graded process. Here we show that regenerative CICR develops as an all-or-none event in cultured rat dorsal root ganglion neurons in which ryanodine receptors have been sensitized to Ca
2+
by caffeine. We used indo-1-based microfluorimetry in combination with whole-cell patch-clamp recording to characterize the relationship between Ca
2+
influx and Ca
2+
release. Regenerative release of Ca
2+
was triggered when action potential-induced Ca
2+
influx increased the intracellular Ca
2+
concentration ([Ca
2+
]
i
) above threshold. The threshold was modulated by caffeine and intraluminal Ca
2+
. A relative refractory period followed CICR. The pharmacological profile of the response was consistent with Ca
2+
influx through voltage-gated Ca
2+
channels triggering release from ryanodine-sensitive stores. The activation of a suprathreshold response increased more than fivefold the amplitude and duration of the [Ca
2+
]
i
transient. The switch to a suprathreshold response was regulated very precisely in that addition of a single action potential to the stimulus train was sufficient for this transformation. Confocal imaging experiments showed that CICR facilitated propagation of the Ca
2+
signal from the plasmalemma to the nucleus. This all-or-none reaction may serve as a switch that determines whether a given electrical signal will be transduced into a local or widespread increase in [Ca
2+
]
i
.
Details
- Title: Subtitle
- All-or-None Ca2+ Release from Intracellular Stores Triggered by Ca2+ Influx through Voltage-Gated Ca2+ Channels in Rat Sensory Neurons
- Creators
- Yuriy M UsachevStanley A Thayer
- Resource Type
- Journal article
- Publication Details
- The Journal of neuroscience, Vol.17(19), pp.7404-7414
- DOI
- 10.1523/JNEUROSCI.17-19-07404.1997
- PMID
- 9295386
- NLM abbreviation
- J Neurosci
- ISSN
- 0270-6474
- eISSN
- 1529-2401
- Publisher
- Society for Neuroscience
- Language
- English
- Date published
- 10/01/1997
- Academic Unit
- Iowa Neuroscience Institute; Anesthesia; Neuroscience and Pharmacology
- Record Identifier
- 9984040359602771
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