 |
 Previous Article
The Journal of Neuroscience, February 15, 2000, 20(4):1643-1655
Kinematics and Modeling of Leech Crawling: Evidence for an
Oscillatory Behavior Produced by Propagating Waves of Excitation
Timothy W.
Cacciatore1,
Roman
Rozenshteyn2, and
William B.
Kristan Jr1, 2
1 Neurosciences Graduate Program and
2 Department of Biology, University of California, La
Jolla, California 92093
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.
Key words:
central pattern generator; locomotion; crawling; computer
simulation; behavior; leech
Copyright © 2000 Society for Neuroscience 0270-6474/00/2041643-13$05.00/0
This article has been cited by other articles:
|
|
|
|
 
J. G. Puhl and K. A. Mesce
Dopamine Activates the Motor Pattern for Crawling in the Medicinal Leech
J. Neurosci.,
April 16, 2008;
28(16):
4192 - 4200.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. A. Woods Jr, S. J. Fusillo, and B. A. Trimmer
Dynamic properties of a locomotory muscle of the tobacco hornworm Manduca sexta during strain cycling and simulated natural crawling
J. Exp. Biol.,
March 15, 2008;
211(6):
873 - 882.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. Trimmer and J. Issberner
Kinematics of Soft-bodied, Legged Locomotion in Manduca sexta Larvae
Biol. Bull.,
April 1, 2007;
212(2):
130 - 142.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. L. Briggman and W. B. Kristan Jr
Imaging dedicated and multifunctional neural circuits generating distinct behaviors.
J. Neurosci.,
October 18, 2006;
26(42):
10925 - 10933.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Cornford, W. B. Kristan III, S. Malnove, W. B. Kristan Jr, and K. A. French
Functions of the subesophageal ganglion in the medicinal leech revealed by ablation of neuromeres in embryos
J. Exp. Biol.,
February 1, 2006;
209(3):
493 - 503.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. L. Briggman, H. D. I. Abarbanel, and W. B. Kristan Jr.
Optical Imaging of Neuronal Populations During Decision-Making
Science,
February 11, 2005;
307(5711):
896 - 901.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Mazzoni, E. Garcia-Perez, D. Zoccolan, S. Graziosi, and V. Torre
Quantitative Characterization and Classification of Leech Behavior
J Neurophysiol,
January 1, 2005;
93(1):
580 - 593.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. L. Taylor, G. W. Cottrell, D. Kleinfeld, and W. B. Kristan Jr
Imaging Reveals Synaptic Targets of a Swim-Terminating Neuron in the Leech CNS
J. Neurosci.,
December 10, 2003;
23(36):
11402 - 11410.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. Esch, K. A. Mesce, and W. B. Kristan
Evidence for Sequential Decision Making in the Medicinal Leech
J. Neurosci.,
December 15, 2002;
22(24):
11045 - 11054.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
