Mapping of IP(3)-mediated Ca(2+) signals in single human neuroblastoma SH-SY5Y cells: cell volume shaping the Ca(2+) signal.

Abstract

Fast confocal laser-scanning microscopy was used to study spatiotemporal properties of IP(3)-mediated Ca(2+) release signals in human SH-SY5Y neuroblastoma cells. [Ca(2+)](i) increases were not affected by ryanodine (30 microgM) or caffeine (10 mM) and largely insensitive to removal of external Ca(2+), indicating predominance of IP(3)-induced Ca(2+) release. Ca(2+) signals evoked by high concentration (10 microM) of the muscarinic agonist carbachol appeared as self-propagating waves initiating in cell processes. At low carbachol concentrations (500 nM) Ca(2+) changes in most cells displayed striking spatiotemporal heterogeneity. The Ca(2+) response in the cell body was delayed and had a smaller amplitude and a slower rise time than that in processes. Ca(2+) changes in processes either occurred in a homogeneous manner throughout the whole process or were sometimes confined to hot spots. Regional differences in surface-to-volume ratio appear to be critical clues that determine the spatiotemporal pattern of intracellular Ca(2+) release signals.

• Authors: K van Acker, B Bautmans, G Bultynck, K Maes, A F Weidema, P de Smet, J B Parys, H de Smedt, L Missiaen, G Callewaert
• Journal: Journal of neurophysiology (J Neurophysiol) Vol. 83 Issue 2 Pg. 1052-7 (Feb 2000) ISSN: 0022-3077 [Print] United States
• PMID: 10669516 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Calcium Channels
• Central Nervous System Stimulants
• Cholinergic Agonists
• ITPR1 protein, human
• Inositol 1,4,5-Trisphosphate Receptors
• Receptors, Cytoplasmic and Nuclear
• Caffeine
• Inositol 1,4,5-Trisphosphate
• Carbachol
• Calcium

Topics

• Caffeine (pharmacology)
• Calcium (metabolism)
• Calcium Channels (chemistry, physiology)
• Calcium Signaling (drug effects, physiology)
• Carbachol (pharmacology)
• Cell Size (physiology)
• Central Nervous System Stimulants (pharmacology)
• Cholinergic Agonists (pharmacology)
• Humans
• Image Processing, Computer-Assisted
• Inositol 1,4,5-Trisphosphate (pharmacology)
• Inositol 1,4,5-Trisphosphate Receptors
• Microscopy, Confocal
• Microscopy, Fluorescence
• Neuroblastoma
• Receptors, Cytoplasmic and Nuclear (chemistry, physiology)
• Tumor Cells, Cultured (chemistry, cytology, physiology)