UMMS Affiliation

Department of Physiology

Publication Date

2004-02-06

Document Type

Article

Subjects

Animals; Caffeine; Calcium; Calcium Signaling; Hypothalamus; Membrane Potentials; Mice; Neurons; Patch-Clamp Techniques; Presynaptic Terminals; Ryanodine Receptor Calcium Release Channel; Subcellular Fractions

Disciplines

Life Sciences | Medicine and Health Sciences | Neuroscience and Neurobiology

Abstract

Localized, brief Ca2+ transients (Ca2+ syntillas) caused by release from intracellular stores were found in isolated nerve terminals from magnocellular hypothalamic neurons and examined quantitatively using a signal mass approach to Ca2+ imaging. Ca2+ syntillas (scintilla, L., spark, from a synaptic structure, a nerve terminal) are caused by release of approximately 250,000 Ca ions on average by a Ca2+ flux lasting on the order of tens of milliseconds and occur spontaneously at a membrane potential of -80 mV. Syntillas are unaffected by removal of extracellular Ca2+, are mediated by ryanodine receptors (RyRs) and are increased in frequency, in the absence of extracellular Ca2+, by physiological levels of depolarization. This represents the first direct demonstration of mobilization of Ca2+ from intracellular stores in neurons by depolarization without Ca2+ influx. The regulation of syntillas by depolarization provides a new link between neuronal activity and cytosolic [Ca2+] in nerve terminals.

DOI of Published Version

10.1523/JNEUROSCI.4286-03.2004

Source

J Neurosci. 2004 Feb 4;24(5):1226-35. Link to article on publisher's site

Journal/Book/Conference Title

The Journal of neuroscience : the official journal of the Society for Neuroscience

Comments

Co-author Cristina M. Velazquez-Marrero is a student in the Neuroscience program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.

Related Resources

Link to Article in PubMed

PubMed ID

14762141

Share

COinS