Cacciatore, TW;
Rozenshteyn, R;
W, B;
(2000)
A kinematic and computational study of leech crawling: Support for a CPG based on travelling waves of excitation.
Journal of Neuroscience
, 20
1643 - 1655.
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Abstract
Many well characterized central pattern generators (CPGs) underlie behaviors (e.g., swimming, flight, heartbeat) that require regular rhythmicity and strict phase relationships. Here, we examine the organization of a CPG for leech crawling, a behavior whose success depends more on its flexibility than on its precise coordination. We examined the organization of this CPG by first characterizing the kinematics of crawling steps in normal and surgically manipulated animals, then by exploring its features in a simple neuronal model. The behavioral observations revealed the following. (1) Intersegmental coordination varied considerably with step duration, whereas the rates of elongation and contraction within individual segments were relatively constant. (2) Steps were generated in the absence of both head and tail brains, implying that midbody ganglia contain a CPG for step production. (3) Removal of sensory feedback did not affect step coordination or timing. (4) Imposed stretch greatly lengthened transitions between elongation and contraction, indicating that sensory pathways feed back onto the CPG. A simple model reproduced essential features of the observed kinematics. This model consisted of an oscillator that initiates propagating segmental waves of activity in excitatory neuronal chains, along with a parallel descending projection; together, these pathways could produce the observed intersegmental lags, coordination between phases, and step duration. We suggest that the proposed model is well suited to be modified on a step-by-step basis and that crawling may differ substantially from other described CPGs, such as that for swimming in segmented animals, where individual segments produce oscillations that are strongly phase-locked to one another.
| Type: | Article |
|---|---|
| Title: | A kinematic and computational study of leech crawling: Support for a CPG based on travelling waves of excitation. |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. The license allows you to copy, distribute, and transmit the work, as well as adapting it. However, you must attribute the work to the author (but not in any way that suggests that they endorse you or your use of the work), and cannot use the work for commercial purposes without prior permission of the author. If you alter or build upon this work, you can distribute the resulting work only under the same or similar license to this one. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA. |
| UCL classification: | UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology |
| URI: | https://discovery.ucl.ac.uk/id/eprint/82290 |
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