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: 97/5/3407    most recent 00939.2006v3 00939.2006v2 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 (3) Citing Articles via Google Scholar Google Scholar Articles by Fort, T. J. Articles by Miller, M. W. Search for Related Content PubMed PubMed Citation Articles by Fort, T. J. Articles by Miller, M. W.

Regulation of the Crab Heartbeat by Crustacean Cardioactive Peptide (CCAP): Central and Peripheral Actions

¹Institute of Neurobiology and Department of Anatomy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico; ²Zentrum für Molekulare Biomedizin, Friedrich-Schiller-Universität Jena, Jena, Germany; and ³Fishberg Department of Neuroscience, Mount Sinai School of Medicine, New York, New York

Submitted 5 September 2006; accepted in final form 31 January 2007

In regulating neurophysiological systems, neuromodulators exert multiple actions at multiple sites in such a way as to control the activity in an integrated manner. We are studying how this happens in a simple central pattern generator (CPG)–effector system, the heart of the blue crab Callinectes sapidus. The rhythmic contractions of this heart are neurogenic, driven by rhythmic motor patterns generated by the cardiac ganglion (CG). In this study, we used anatomical and physiological methods to examine the sources and actions on the system of crustacean cardioactive peptide (CCAP). Immunohistochemical localization revealed a plexus of CCAP-immunoreactive fibers in the pericardial organs (POs), neurohemal structures from which blood-borne neurohormones reach the heart. Combined backfill and immunohistochemical experiments indicated that the CCAP in the POs originated from a large contralateral neuron in each thoracic neuromere. In physiological experiments, we examined the actions of exogenous CCAP on the intact working heart, on the semi-intact heart in which we could record the motor patterns as well as the muscle contractions, and on the isolated CG. CCAP had strong positive inotropic and chronotropic effects. Dissection of these effects in terms of dose dependency, time course, and the preparation type in which they occurred suggested that they were produced by the interaction of three primary actions of CCAP exerted both on the heart muscle and on the CG. We conclude that CCAP released from the POs as a neurohormone regulates the crab heart by multiple actions on both the central and peripheral components of this model CPG–effector system.

This article has been cited by other articles:

				M. S. Kirby and M. P. Nusbaum Peptide Hormone Modulation of a Neuronally Modulated Motor Circuit J Neurophysiol, December 1, 2007; 98(6): 3206 - 3220. [Abstract] [Full Text] [PDF]

				T. J. Fort, V. Brezina, and M. W. Miller Regulation of the Crab Heartbeat by FMRFamide-Like Peptides: Multiple Interacting Effects on Center and Periphery J Neurophysiol, November 1, 2007; 98(5): 2887 - 2902. [Abstract] [Full Text] [PDF]

				V. Medan, D. Oliva, and D. Tomsic Characterization of Lobula Giant Neurons Responsive to Visual Stimuli That Elicit Escape Behaviors in the Crab Chasmagnathus J Neurophysiol, October 1, 2007; 98(4): 2414 - 2428. [Abstract] [Full Text] [PDF]

				N. D. Cruz-Bermudez and E. Marder Multiple modulators act on the cardiac ganglion of the crab, Cancer borealis J. Exp. Biol., August 15, 2007; 210(16): 2873 - 2884. [Abstract] [Full Text] [PDF]