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

This Article 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 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 SIMMERS, A. J. Articles by BUSH, B. M. H. Search for Related Content PubMed Articles by SIMMERS, A. J. Articles by BUSH, B. M. H.

Journal of Experimental Biology 104,163-181 (1983)
Published by Company of Biologists 1983

Motor Programme Switching in the Ventilatory System of Carcinus Maenas: The Neuronal Basis of Bimodal Scaphognathite Beating

A. JOHN SIMMERS ¹ and BRIAN M. H. BUSH ²

¹ Department of Physiology, University of Bristol, School of Veterinary Science, Park Row, Bristol, BS1 5LS; C.N.R.S. Laboratoire de Neurobiologie Compared, Place du Docteur Bcrtrand Peyneau, 20 Arcachon, France
² Department of Physiology, University of Bristol, School of Veterinary Science, Park Row, Bristol, BS1 5LS

Intracellular recordings have been made from ventilatory neurones in semi-isolated and isolated thoracic ganglia of the crab Carcinus during spontaneous switching between the two motor programmes underlying forward and reversed beating of the scaphognathites (SGs).

Ventilatory reversals are dependent upon the central activation of two subgroups of motoneurones which are normally silent, and different from those driving the same SG muscles during the forward rhythm. Two further subgroups of motoneurones remain active throughout both rhythm modes.

The results suggest that both motor output patterns are produced mainly by periodic inhibitory synaptic input from the same oscillator network, and that neural switching between the rhythm modes occurs directly at the level of the motoneurones themselves.

It appears that both sets of ‘forward’ and ‘reversal’ motoneurones are driven continuously throughout oscillator activity, and that bursting activity in these sets is gated by the selective application or removal of additional, tonic inhibition.

Key words: Motor programme (switching), ventilatory system, crab motoneurones

Submitted on September 20, 1982
Accepted on November 23, 1982

This article has been cited by other articles:

				L. Corbari, P. Carbonel, and J.-C. Massabuau The early life history of tissue oxygenation in crustaceans: the strategy of the myodocopid ostracod Cylindroleberis mariae J. Exp. Biol., February 15, 2005; 208(4): 661 - 670. [Abstract] [Full Text] [PDF]

				L. Corbari, P. Carbonel, and J.-C. Massabuau How a low tissue O2 strategy could be conserved in early crustaceans: the example of the podocopid ostracods J. Exp. Biol., December 1, 2004; 207(25): 4415 - 4425. [Abstract] [Full Text] [PDF]