Mechanisms of dendritic calcium signaling in fly neurons

Oertner, T. G., Brotz, T. M., Borst, A. (January 2001) Mechanisms of dendritic calcium signaling in fly neurons. Journal of Neurophysiology, 85 (1). pp. 439-447. ISSN 0022-3077

URL: http://www.ncbi.nlm.nih.gov/pubmed/11152745

Abstract

We examined the mechanisms underlying dendritic calcium accumulation in lobula plate tangential cells of the fly visual system using an in vitro preparation of the fly brain. Local visual stimulation evokes a localized calcium signal in the dendrites of these cells in vivo. Here we show that a similar localized calcium accumulation can be elicited in vitro by focal iontophoretic application of the cholinergic agonist carbachol. The calcium signal had at least two sources: first, voltage-dependent calcium channels contributed to the carbachol-induced signal and were concentrated on the dendrite, the soma, and the terminal ramification of the axon. However, the dendritic calcium signal induced by carbachol stimulation was only weakly dependent on membrane depolarization. The most likely explanation for the second, voltage-independent part of the dendritic calcium signal is calcium entry through nicotinic acetylcholine receptors. We found no indication of second-messenger or calcium-mediated calcium release from intracellular stores. In summary, the characteristic spatiotemporal calcium signals in the dendrites of lobula plate tangential cells can be reproduced in vitro, and result from a combination of voltage- and ligand-gated calcium influx.

Item Type:	Paper
Uncontrolled Keywords:	INTRINSIC ELECTROPHYSIOLOGICAL CHARACTERISTICS BLOWFLY CALLIPHORA-ERYTHROCEPHALA MOTION SENSITIVE INTERNEURONS PLATE TANGENTIAL CELLS GIANT VERTICAL CELLS LOBULA PLATE VISUAL INTERNEURONS HORIZONTAL CELLS DIRECTION SELECTIVITY MEMBRANE-PROPERTIES
Subjects:	organism description > animal > insect > Drosophila organs, tissues, organelles, cell types and functions > sub-cellular tissues: types and functions > calcium channel organs, tissues, organelles, cell types and functions > cell types and functions > cell functions > cell signaling organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons
CSHL Authors:	Oertner, Thomas G.
Communities:	CSHL labs > Svoboda lab
Depositing User:	Matt Covey
Date:	January 2001
Date Deposited:	17 Jan 2014 20:45
Last Modified:	17 Jan 2014 20:45
Related URLs:	Publisher
URI:	https://repository.cshl.edu/id/eprint/29281

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