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Feedback from peripheral musculature to central pattern generator in the neurogenic heart of the crab Callinectes sapidus: role of mechanosensitive dendrites.
J Neurophysiol 2010; 103(1):83-96JN

Abstract

The neurogenic heart of decapod crustaceans is a very simple, self-contained, model central pattern generator (CPG)-effector system. The CPG, the nine-neuron cardiac ganglion (CG), is embedded in the myocardium itself; it generates bursts of spikes that are transmitted by the CG's five motor neurons to the periphery of the system, the myocardium, to produce its contractions. Considerable evidence suggests that a CPG-peripheral loop is completed by a return feedback pathway through which the contractions modify, in turn, the CG motor pattern. One likely pathway is provided by dendrites, presumably mechanosensitive, that the CG neurons project into the adjacent myocardial muscle. Here we have tested the role of this pathway in the heart of the blue crab, Callinectes sapidus. We performed "de-efferentation" experiments in which we cut the motor neuron axons to the myocardium and "de-afferentation" experiments in which we cut or ligated the dendrites. In the isolated CG, these manipulations had no effect on the CG motor pattern. When the CG remained embedded in the myocardium, however, these manipulations, interrupting either the efferent or afferent limb of the CPG-peripheral loop, decreased contraction amplitude, increased the frequency of the CG motor neuron spike bursts, and decreased the number of spikes per burst and burst duration. Finally, passive stretches of the myocardium likewise modulated the spike bursts, an effect that disappeared when the dendrites were cut. We conclude that feedback through the dendrites indeed operates in this system and suggest that it completes a loop through which the system self-regulates its activity.

Authors+Show Affiliations

Institute of Neurobiology, University of Puerto Rico, 201 Blvd. del Valle, San Juan, Puerto Rico 00901.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

19828726

Citation

García-Crescioni, Keyla, et al. "Feedback From Peripheral Musculature to Central Pattern Generator in the Neurogenic Heart of the Crab Callinectes Sapidus: Role of Mechanosensitive Dendrites." Journal of Neurophysiology, vol. 103, no. 1, 2010, pp. 83-96.
García-Crescioni K, Fort TJ, Stern E, et al. Feedback from peripheral musculature to central pattern generator in the neurogenic heart of the crab Callinectes sapidus: role of mechanosensitive dendrites. J Neurophysiol. 2010;103(1):83-96.
García-Crescioni, K., Fort, T. J., Stern, E., Brezina, V., & Miller, M. W. (2010). Feedback from peripheral musculature to central pattern generator in the neurogenic heart of the crab Callinectes sapidus: role of mechanosensitive dendrites. Journal of Neurophysiology, 103(1), pp. 83-96. doi:10.1152/jn.00561.2009.
García-Crescioni K, et al. Feedback From Peripheral Musculature to Central Pattern Generator in the Neurogenic Heart of the Crab Callinectes Sapidus: Role of Mechanosensitive Dendrites. J Neurophysiol. 2010;103(1):83-96. PubMed PMID: 19828726.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Feedback from peripheral musculature to central pattern generator in the neurogenic heart of the crab Callinectes sapidus: role of mechanosensitive dendrites. AU - García-Crescioni,Keyla, AU - Fort,Timothy J, AU - Stern,Estee, AU - Brezina,Vladimir, AU - Miller,Mark W, Y1 - 2009/10/14/ PY - 2009/10/16/entrez PY - 2009/10/16/pubmed PY - 2010/3/31/medline SP - 83 EP - 96 JF - Journal of neurophysiology JO - J. Neurophysiol. VL - 103 IS - 1 N2 - The neurogenic heart of decapod crustaceans is a very simple, self-contained, model central pattern generator (CPG)-effector system. The CPG, the nine-neuron cardiac ganglion (CG), is embedded in the myocardium itself; it generates bursts of spikes that are transmitted by the CG's five motor neurons to the periphery of the system, the myocardium, to produce its contractions. Considerable evidence suggests that a CPG-peripheral loop is completed by a return feedback pathway through which the contractions modify, in turn, the CG motor pattern. One likely pathway is provided by dendrites, presumably mechanosensitive, that the CG neurons project into the adjacent myocardial muscle. Here we have tested the role of this pathway in the heart of the blue crab, Callinectes sapidus. We performed "de-efferentation" experiments in which we cut the motor neuron axons to the myocardium and "de-afferentation" experiments in which we cut or ligated the dendrites. In the isolated CG, these manipulations had no effect on the CG motor pattern. When the CG remained embedded in the myocardium, however, these manipulations, interrupting either the efferent or afferent limb of the CPG-peripheral loop, decreased contraction amplitude, increased the frequency of the CG motor neuron spike bursts, and decreased the number of spikes per burst and burst duration. Finally, passive stretches of the myocardium likewise modulated the spike bursts, an effect that disappeared when the dendrites were cut. We conclude that feedback through the dendrites indeed operates in this system and suggest that it completes a loop through which the system self-regulates its activity. SN - 1522-1598 UR - https://www.unboundmedicine.com/medline/citation/19828726/Feedback_from_peripheral_musculature_to_central_pattern_generator_in_the_neurogenic_heart_of_the_crab_Callinectes_sapidus:_role_of_mechanosensitive_dendrites_ L2 - http://www.physiology.org/doi/full/10.1152/jn.00561.2009?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -