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: 91/5/2297    most recent 00787.2003v1 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 ISI Web of Science 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 (7) Citing Articles via Google Scholar Google Scholar Articles by Yu, X. Articles by Baxter, D. A. Search for Related Content PubMed PubMed Citation Articles by Yu, X. Articles by Baxter, D. A.

Modeling Interactions Between Electrical Activity and Second-Messenger Cascades in Aplysia Neuron R15

Center for Computational Biomedicine, Department of Neurobiology and Anatomy, The University of Texas–Houston Medical School, Houston, Texas 77030

Submitted 13 August 2003; accepted in final form 19 December 2003

The biophysical properties of neuron R15 in Aplysia endow it with the ability to express multiple modes of oscillatory electrical activity, such as beating and bursting. Previous modeling studies examined the ways in which membrane conductances contribute to the electrical activity of R15 and the ways in which extrinsic modulatory inputs alter the membrane conductances by biochemical cascades and influence the electrical activity. The goals of the present study were to examine the ways in which electrical activity influences the biochemical cascades and what dynamical properties emerge from the ongoing interactions between electrical activity and these cascades. The model proposed by Butera et al. in 1995 was extended to include equations for the binding of Ca²⁺ to calmodulin (CaM) and the actions of Ca²⁺/CaM on both adenylyl cyclase and phosphodiesterase. Simulations indicated that levels of cAMP oscillated during bursting and that these oscillations were approximately antiphasic to the oscillations of Ca²⁺. In the presence of cAMP oscillations, brief perturbations could switch the electrical activity between bursting and beating (bistability). Compared with a constant-cAMP model, oscillations of cAMP substantially expanded the range of bistability. Moreover, the integrated electrical/biochemical model simulated some early experimental results such as activity-dependent inactivation of the anomalous rectifier. The results of the present study suggest that the endogenous activity of R15 depends, in part, on interactions between electrical activity and biochemical cascades.

This article has been cited by other articles:

				G. G. Holz, E. Heart, and C. A. Leech Synchronizing Ca2+ and cAMP oscillations in pancreatic {beta}-cells: a role for glucose metabolism and GLP-1 receptors?Focus on "Regulation of cAMP dynamics by Ca2+ and G protein-coupled receptors in the pancreatic {beta}-cell: a computational approach" Am J Physiol Cell Physiol, January 1, 2008; 294(1): C4 - C6. [Full Text] [PDF]

				L. E. Fridlyand, M. C. Harbeck, M. W. Roe, and L. H. Philipson Regulation of cAMP dynamics by Ca2+ and G protein-coupled receptors in the pancreatic -cell: a computational approach Am J Physiol Cell Physiol, December 1, 2007; 293(6): C1924 - C1933. [Abstract] [Full Text] [PDF]

				D. Willoughby and D. M. F. Cooper Organization and Ca2+ Regulation of Adenylyl Cyclases in cAMP Microdomains Physiol Rev, July 1, 2007; 87(3): 965 - 1010. [Abstract] [Full Text] [PDF]

				D. Willoughby and D. M. F. Cooper Ca2+ stimulation of adenylyl cyclase generates dynamic oscillations in cyclic AMP J. Cell Sci., March 1, 2006; 119(5): 828 - 836. [Abstract] [Full Text] [PDF]

				R. A. Baines Synaptic Strengthening Mediated by Bone Morphogenetic Protein-Dependent Retrograde Signaling in the Drosophila CNS J. Neurosci., August 4, 2004; 24(31): 6904 - 6911. [Abstract] [Full Text] [PDF]