QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online August 9, 2007
Journal of Experimental Biology 210, 2912-2922 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.006874

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted 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 Google Scholar Google Scholar Articles by Smarandache, C. R. Articles by Stein, W. Search for Related Content PubMed PubMed Citation Articles by Smarandache, C. R. Articles by Stein, W. Social Bookmarking                         What's this?

Sensory-induced modification of two motor patterns in the crab, Cancer pagurus

Carmen R. Smarandache and Wolfgang Stein^*

Institute of Neurobiology, Ulm University, D-89069 Ulm, Germany

^* Author for correspondence (e-mail: wstein{at}neurobiologie.de)

Accepted 16 May 2007

Sensory input is pervasive among motor networks and continuously adapts motor patterns to changing circumstances. To elucidate common principles of sensorimotor integration, it is beneficial to characterize sensory influences on motor network operation and compare these influences between species. To facilitate such comparison, we have studied the influence of the anterior gastric receptor (AGR) – a proprioceptor that has been characterized in detail in two lobster species – on the pyloric (filtering of food) and gastric mill (chewing of food) motor patterns in the crab Cancer pagurus.

AGR has a bipolar cell body in the stomatogastric ganglion; it was activated by tension increase in gastric mill powerstroke muscles. While two spike initiation zones accounted for its spontaneous activity, active membrane properties (sag potentials, spike frequency adaptation) contributed to the AGR response to current injections.

When activated, AGR diminished spike activities in two pyloric motor neurons and prolonged the pyloric cycle period. Furthermore, AGR excited gastric mill protractor neurons, inhibited the retractor neuron and evoked phase-independent resetting of the gastric mill rhythm. Repetitive spike trains entrained the rhythm to both longer and shorter cycle periods. All AGR actions seemed to be mediated via at least two premotor projection neurons in the spatially distant commissural ganglia. The response of the gastric mill neurons was independent of AGR firing frequency.

Our results suggest that homologous proprioceptors can elicit similar effects on motor patterns while utilizing different mechanisms. This work thus provides an initial framework for future studies to determine underlying common principles.

Key words: Cancer pagurus, stomatogastric ganglion, projection neuron, central pattern generation, sensory regulation

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				U. B. S. Hedrich, C. R. Smarandache, and W. Stein Differential Activation of Projection Neurons by Two Sensory Pathways Contributes to Motor Pattern Selection J Neurophysiol, November 1, 2009; 102(5): 2866 - 2879. [Abstract] [Full Text] [PDF]

				U. B. S. Hedrich and W. Stein Characterization of a descending pathway: activation and effects on motor patterns in the brachyuran crustacean stomatogastric nervous system J. Exp. Biol., August 15, 2008; 211(16): 2624 - 2637. [Abstract] [Full Text] [PDF]

				D. M. Blitz, R. S. White, S. R. Saideman, A. Cook, A. E. Christie, F. Nadim, and M. P. Nusbaum A newly identified extrinsic input triggers a distinct gastric mill rhythm via activation of modulatory projection neurons J. Exp. Biol., March 15, 2008; 211(6): 1000 - 1011. [Abstract] [Full Text] [PDF]

				M. P. Beenhakker, M. S. Kirby, and M. P. Nusbaum Mechanosensory Gating of Proprioceptor Input to Modulatory Projection Neurons J. Neurosci., December 26, 2007; 27(52): 14308 - 14316. [Abstract] [Full Text] [PDF]