HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 100/2/868    most recent 90464.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Worrell, J. W. Articles by Levine, R. B. Search for Related Content PubMed PubMed Citation Articles by Worrell, J. W. Articles by Levine, R. B.

Characterization of Voltage-Dependent Ca²⁺ Currents in Identified Drosophila Motoneurons In Situ

¹Division of Neurobiology, ²Graduate Program in Physiological Sciences, and ³Department of Physiology, University of Arizona, Tucson, Arizona

Submitted 13 April 2008; accepted in final form 5 June 2008

Voltage-dependent Ca²⁺ channels contribute to neurotransmitter release, integration of synaptic information, and gene regulation within neurons. Thus understanding where diverse Ca²⁺ channels are expressed is an important step toward understanding neuronal function within a network. Drosophila provides a useful model for exploring the function of voltage-dependent Ca²⁺ channels in an intact system, but Ca²⁺ currents within the central processes of Drosophila neurons in situ have not been well described. The aim of this study was to characterize voltage-dependent Ca²⁺ currents in situ from identified larval motoneurons. Whole cell recordings from the somata of identified motoneurons revealed a significant influence of extracellular Ca²⁺ on spike shape and firing rate. Using whole cell voltage clamp, along with blockers of Na⁺ and K⁺ channels, a Ca²⁺-dependent inward current was isolated. The Drosophila genome contains three genes with homology to vertebrate voltage-dependent Ca²⁺ channels: Dmca1A, Dmca1D, and Dm1G. We used mutants of Dmca1A and Dmca1D as well as targeted expression of an RNAi transgene to Dmca1D to determine the genes responsible for the voltage-dependent Ca²⁺ current recorded from two identified motoneurons. Our results implicate Dmca1D as the major contributor to the voltage-dependent Ca²⁺ current recorded from the somatodendritic processes of motoneurons, whereas Dmca1A has previously been localized to the presynaptic terminal where it is essential for neurotransmitter release. Altered firing properties in cells from both Dmca1D and Dmca1A mutants indicate a role for both genes in shaping firing properties.

This article has been cited by other articles:

				H. Gu, S. A. Jiang, J. M. Campusano, J. Iniguez, H. Su, A. A. Hoang, M. Lavian, X. Sun, and D. K. O'Dowd Cav2-Type Calcium Channels Encoded by cac Regulate AP-Independent Neurotransmitter Release at Cholinergic Synapses in Adult Drosophila Brain J Neurophysiol, January 1, 2009; 101(1): 42 - 53. [Abstract] [Full Text] [PDF]