Modelling spinal circuitry involved in locomotor pattern generation: insights from the effects of afferent stimulation

Rybak, Ilya A.; Stecina, Katinka; Shevtsova, Natalia A.; McCrea, David A.

doi:10.1113/jphysiol.2006.118711

Cited by 182 publications

(158 citation statements)

References 49 publications

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“…A more complete explanation of these observations can be found elsewhere (Rybak et al, 2006b). In the case of extensor group I afferents, we suggest that they have access to both the RG and PF networks.…”

Section: Features Of the Two-level Cpg: The Role Of The Pattern Formamentioning

confidence: 69%

“…During these sensory stimulations and non-resetting deletions (see Rybak et al, 2006a), PF network activity does not strictly follow that of the RG. Example simulations reproducing other types of sensory control of CPG operation are shown in Rybak et al (2006b). In summary, our modeling studies have demonstrated that a simple two-level CPG organization with separate rhythm generator and pattern formation networks can provide a plausible explanation for a number of features of real CPG network operation.…”

Section: Features Of the Two-level Cpg: The Role Of The Pattern Formamentioning

confidence: 79%

“…Figure 2 shows a more detailed schematic of the model including the neural pathways providing sensory control by extensor group I afferents of both the RG and PF levels of the CPG. The effects of other sensory inputs to the model are presented elsewhere (Rybak et al, 2006b). …”

Section: Implementation Of a Two-level Cpg Modelmentioning

confidence: 99%

“…In B1 (and similar to B2) extensor phase group I stimulation increased PF-E population activity that enhanced and prolonged extensor motoneuron activity without changing the locomotor period (see equal length arrows at the bottom). From Rybak et al (2006b).…”

Section: Fig 1 Schematic Representations Of Half-center Cpg Modelsmentioning

confidence: 99%

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Organization of mammalian locomotor rhythm and pattern generation

McCrea

Rybak

2008

Brain Research Reviews

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506

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Central pattern generators (CPGs) located in the spinal cord produce the coordinated activation of flexor and extensor motoneurons during locomotion. Previously proposed architectures for the spinal locomotor CPG have included the classical half-center oscillator and the unit burst generator (UBG) comprised of multiple coupled oscillators. We have recently proposed another organization in which a two-level CPG has a common rhythm generator (RG) that controls the operation of the pattern formation (PF) circuitry responsible for motoneuron activation. These architectures are discussed in relation to recent data obtained during fictive locomotion in the decerebrate cat. The data show that the CPG can maintain the period and phase of locomotor oscillations both during spontaneous deletions of motoneuron activity and during sensory stimulation affecting motoneuron activity throughout the limb. The proposed two-level CPG organization has been investigated with a computational model which incorporates interactions between the CPG, spinal circuits and afferent inputs. The model includes interacting populations of spinal interneurons and motoneurons modeled in the Hodgkin-Huxley style. Our simulations demonstrate that a relatively simple CPG with separate RG and PF networks can realistically reproduce many experimental phenomena including spontaneous deletions of motoneuron activity and a variety of effects of afferent stimulation. The model suggests plausible explanations for a number of features of real CPG operation that would be difficult to explain in the framework of the classical single-level CPG organization. Some modeling predictions and directions for further studies of locomotor CPG organization are discussed. KeywordsCPG; computational models; spinal cord; decerebrate; cat Half-center organization of the central pattern generatorMore than 90 years ago, T. Graham Brown (1911) demonstrated that the cat spinal cord can generate a locomotor rhythm in the absence of input from higher centers and afferent feedback. These and later investigations led to the widely accepted concept of central pattern generators Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptBrain Res Rev. Author manuscript; available in PMC 2009 January 1. Published in final edited form as:Brain Res Rev. 2008 January ; 57(1): 134-146. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript (CPGs) which reside within the central nervous systems of invertebrates and vertebrates and control various rhythmic movements. Graham Brown (1914) also proposed...

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Section: Features Of the Two-level Cpg: The Role Of The Pattern Formamentioning

confidence: 69%

Section: Features Of the Two-level Cpg: The Role Of The Pattern Formamentioning

confidence: 79%

Section: Implementation Of a Two-level Cpg Modelmentioning

confidence: 99%

Section: Fig 1 Schematic Representations Of Half-center Cpg Modelsmentioning

confidence: 99%

See 2 more Smart Citations

Organization of mammalian locomotor rhythm and pattern generation

McCrea

Rybak

2008

Brain Research Reviews

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506

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“…While McCrea and colleagues present some compelling evidence in support of a two-layer model, their evidence that the rhythm-generating layer is organised as half-centres is much less convincing. These investigators rely on spontaneous (Lafreniere-Roula and McCrea, 2005;Rybak et al, 2006a) or evoked (Rybak et al, 2006b) "deletions" of activity in single motor nerves that either are ("resetting" deletions) or are not ("non-resetting" deletions) associated with disruptions of rhythm. They reason that since these non-resetting deletions can be seen in either flexor or extensor muscle nerves, the rhythm-generating layer must excite both the flexor and extensor pattern formation half-centres.…”

Section: Pattern Formation and Rhythm-generating Modulesmentioning

confidence: 99%

Strategies for delineating spinal locomotor rhythm-generating networks and the possible role of Hb9 interneurones in rhythmogenesis

Brownstone

Wilson

2008

Brain Research Reviews

136

122

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Despite significant advances in our understanding of pattern generation in invertebrates and lower vertebrates, there have been barriers to the application of the principles learned to the definition of networks underlying mammalian locomotion. Major difficulties have arisen in identifying spinal interneurones in preparations which allow study of neuronal intrinsic properties and the role of identified interneurones in locomotor networks. Recent genetic technologies in which selective expression of fluorescent proteins in specific populations of mouse spinal neurones have provided new avenues of investigation. In this review, we focus on the generation of locomotor rhythm and outline criteria that rhythm-generating neurones might be expected to fulfill. We then examine the extent to which a recently identified population of spinal interneurones, Hb9 interneurones, fulfill these criteria. Finally, we suggest that Hb9 interneurones could be involved in an asymmetric model of locomotor rhythmogenesis through projections of electrotonically coupled rhythmgenerating modules to flexor pattern formation half-centres. The principles learned from studying this population of interneurones have led to strategies to systematically evaluate neurones that may be involved in locomotor rhythmogenesis.

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Biologically Inspired CPG‐Based Locomotion Control System of a Biped Robot Using Nonlinear Oscillators with Phase Resetting

Aoi¹

2013

Interdisciplinary Mechatronics

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Modelling spinal circuitry involved in locomotor pattern generation: insights from the effects of afferent stimulation

Cited by 182 publications

References 49 publications

Organization of mammalian locomotor rhythm and pattern generation

Organization of mammalian locomotor rhythm and pattern generation

Strategies for delineating spinal locomotor rhythm-generating networks and the possible role of Hb9 interneurones in rhythmogenesis

Biologically Inspired CPG‐Based Locomotion Control System of a Biped Robot Using Nonlinear Oscillators with Phase Resetting

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