Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
J Comput Neurosci
2003 Jan 01;141:55-70. doi: 10.1023/a:1021176301776.
Show Gene links
Show Anatomy links
Coordinated motor activity in simulated spinal networks emerges from simple biologically plausible rules of connectivity.
Dale N
.
???displayArticle.abstract???
The spinal motor circuits of the Xenopus embryo have been simulated in a 400-neuron network. To explore the consequences of differing patterns of synaptic connectivity within the network for the generation of the motor rhythm, a system of biologically plausible rules was devised to control synapse formation by three parameters. Each neuron had an intrinsic probability of synapse formation (P(soma), specified by a space constant lambda) that was a monotonically decreasing function of its soma location in the rostro-caudal axis of the simulated network. The neurons had rostral and caudal going axons of specified length (L(axon)) associated with a probability of synapse formation (P(axon)). The final probability of synapse formation was the product of P(soma) and P(axon). Realistic coordinated activity only occurred when L(axon) and the probabilities of interconnection were sufficiently high. Increasing the values of the three network parameters reduced the burst duration, cycle period, and rostro-caudal delay and increased the reliability with which the network functioned as measured by the coefficient of variance of these parameters. Whereas both L(axon) and P(axon) had powerful and consistent effects on network output, the effects of lambda on burst duration and rostro-caudal delay were more variable and depended on the values of the other two parameters. This network model can reproduce the rostro-caudal coordination of swimming without using coupled oscillator theory. The changes in network connectivity and resulting changes in activity explored by the model mimic the development of the motor pattern for swimming in the real embryo.
Brown,
Spike-independent release of ATP from Xenopus spinal neurons evoked by activation of glutamate receptors.
2002, Pubmed,
Xenbase
Brown,
Spike-independent release of ATP from Xenopus spinal neurons evoked by activation of glutamate receptors.
2002,
Pubmed
,
Xenbase
Brown,
Adenosine A1 receptors modulate high voltage-activated Ca2+ currents and motor pattern generation in the xenopus embryo.
2000,
Pubmed
,
Xenbase
Brown,
Modulation of K(+) currents in Xenopus spinal neurons by p2y receptors: a role for ATP and ADP in motor pattern generation.
2002,
Pubmed
,
Xenbase
Buchanan,
Electrophysiological properties of identified classes of lamprey spinal neurons.
1993,
Pubmed
Buchanan,
Identification of excitatory interneurons contributing to generation of locomotion in lamprey: structure, pharmacology, and function.
1989,
Pubmed
Buchanan,
Newly identified 'glutamate interneurons' and their role in locomotion in the lamprey spinal cord.
1987,
Pubmed
Buchanan,
Identification of interneurons with contralateral, caudal axons in the lamprey spinal cord: synaptic interactions and morphology.
1982,
Pubmed
Buchanan,
Neural network simulations of coupled locomotor oscillators in the lamprey spinal cord.
1992,
Pubmed
Cohen,
The nature of the coupling between segmental oscillators of the lamprey spinal generator for locomotion: a mathematical model.
1982,
Pubmed
Dale,
The development of a population of spinal cord neurons and their axonal projections revealed by GABA immunocytochemistry in frog embryos.
1987,
Pubmed
,
Xenbase
Dale,
Kinetic characterization of the voltage-gated currents possessed by Xenopus embryo spinal neurons.
1995,
Pubmed
,
Xenbase
Dale,
Dual-component amino-acid-mediated synaptic potentials: excitatory drive for swimming in Xenopus embryos.
1985,
Pubmed
,
Xenbase
Dale,
Inhibitory neurones of a motor pattern generator in Xenopus revealed by antibodies to glycine.
,
Pubmed
,
Xenbase
Dale,
Regulation of rhythmic movements by purinergic neurotransmitters in frog embryos.
1996,
Pubmed
,
Xenbase
Dale,
A large, sustained Na(+)- and voltage-dependent K+ current in spinal neurons of the frog embryo.
1993,
Pubmed
,
Xenbase
Dale,
Delayed production of adenosine underlies temporal modulation of swimming in frog embryo.
1998,
Pubmed
,
Xenbase
Dale,
Experimentally derived model for the locomotor pattern generator in the Xenopus embryo.
1995,
Pubmed
,
Xenbase
Dale,
Reciprocal inhibitory interneurones in the Xenopus embryo spinal cord.
1985,
Pubmed
,
Xenbase
Ermentrout,
The analysis of synaptically generated traveling waves.
1998,
Pubmed
Hayes,
The distribution of synapses along the spinal cord of an amphibian embryo: an electron microscope study of junction development.
1974,
Pubmed
,
Xenbase
HUGHES,
Studies in embryonic and larval development in Amphibia. II. The spinal motor-root.
1959,
Pubmed
Kotaleski,
Neural mechanisms potentially contributing to the intersegmental phase lag in lamprey.II. Hemisegmental oscillations produced by mutually coupled excitatory neurons.
1999,
Pubmed
Kotaleski,
Neural mechanisms potentially contributing to the intersegmental phase lag in lamprey.I. Segmental oscillations dependent on reciprocal inhibition.
1999,
Pubmed
Kuenzi,
The pharmacology and roles of two K+ channels in motor pattern generation in the Xenopus embryo.
1998,
Pubmed
,
Xenbase
Li,
Defining classes of spinal interneuron and their axonal projections in hatchling Xenopus laevis tadpoles.
2001,
Pubmed
,
Xenbase
Perrins,
Cholinergic contribution to excitation in a spinal locomotor central pattern generator in Xenopus embryos.
1995,
Pubmed
,
Xenbase
Perrins,
Cholinergic and electrical synapses between synergistic spinal motoneurones in the Xenopus laevis embryo.
1995,
Pubmed
,
Xenbase
Roberts,
Development and characterization of commissural interneurones in the spinal cord of Xenopus laevis embryos revealed by antibodies to glycine.
1988,
Pubmed
,
Xenbase
Roberts,
Descending projections and excitation during fictive swimming in Xenopus embryos: neuroanatomy and lesion experiments.
1986,
Pubmed
,
Xenbase
Roberts,
The neuroanatomy of an amphibian embryo spinal cord.
1982,
Pubmed
,
Xenbase
Roberts,
The early development of neurons with GABA immunoreactivity in the CNS of Xenopus laevis embryos.
1987,
Pubmed
,
Xenbase
Roberts,
Mutual Re-excitation with Post-Inhibitory Rebound: A Simulation Study on the Mechanisms for Locomotor Rhythm Generation in the Spinal Cord of Xenopus Embryos.
1990,
Pubmed
,
Xenbase
Sigvardt,
Effects of local oscillator frequency on intersegmental coordination in the lamprey locomotor CPG: theory and experiment.
1996,
Pubmed
Sillar,
Segregation of NMDA and non-NMDA receptors at separate synaptic contacts: evidence from spontaneous EPSPs in Xenopus embryo spinal neurons.
1991,
Pubmed
,
Xenbase
Silver,
Non-NMDA glutamate receptor occupancy and open probability at a rat cerebellar synapse with single and multiple release sites.
1996,
Pubmed
Soffe,
Activity of commissural interneurons in spinal cord of Xenopus embryos.
1984,
Pubmed
,
Xenbase
Soffe,
Functional projection distances of spinal interneurons mediating reciprocal inhibition during swimming in Xenopus tadpoles.
2001,
Pubmed
,
Xenbase
Tunstall,
Longitudinal coordination of motor output during swimming in Xenopus embryos.
1991,
Pubmed
,
Xenbase
Tunstall,
A longitudinal gradient of synaptic drive in the spinal cord of Xenopus embryos and its role in co-ordination of swimming.
1994,
Pubmed
,
Xenbase
van Mier,
Development of early swimming in Xenopus laevis embryos: myotomal musculature, its innervation and activation.
1989,
Pubmed
,
Xenbase
Wall,
A slowly activating Ca(2+)-dependent K+ current that plays a role in termination of swimming in Xenopus embryos.
1995,
Pubmed
,
Xenbase
Wall,
GABAB receptors modulate glycinergic inhibition and spike threshold in Xenopus embryo spinal neurones.
1993,
Pubmed
,
Xenbase
Williams,
Forcing of coupled nonlinear oscillators: studies of intersegmental coordination in the lamprey locomotor central pattern generator.
1990,
Pubmed
Yoshida,
Axon projections of reciprocal inhibitory interneurons in the spinal cord of young Xenopus tadpoles and implications for the pattern of inhibition during swimming and struggling.
1998,
Pubmed
,
Xenbase
