Primitives, premotor drives, and pattern generation: a combined computational and neuroethological perspective

Giszter, Simon F.; Patil, Vidyangi; Hart, Corey B.

doi:10.1016/s0079-6123(06)65020-6

Cited by 81 publications

(78 citation statements)

References 86 publications

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“…They suppose that locomotor pattern generation comprises separated rhythm generation and pattern shaping with layered connections. This division of labor in organizing motion in spinal cord is also supported by our previous work in frog Giszter, 2000 a,b, 2008;Hart and Giszter, 2004;Giszter et al, 2007) and by the results here. The neurons with STA facilitation effects here that may operate to construct motor drive would likely form elements in the pattern-shaping layers of Rybak and McCrea.…”

Section: Pattern Generation and Primitive Organization: Spinal Hierarsupporting

confidence: 90%

“…We now know that microstimulation maps can be labile with experience (Boyce and Lemay, 2009) or as a result of contralateral interactions . It should be noted that the presence of a modular neural organization and of collections of circuits supporting primitives (as discussed here and by Giszter, 2000a, 2008;Hart and Giszter, 2004;Kargo et al, 2009) is not wedded to any specific spatial map organization, and these concepts are quite separate, as discussed in some recent reviews (Giszter et al, 2007;Giszter, 2009). More details of the spatial topography of multiple-neuron activity will be important to address this in the future.…”

Section: Spinal Microstimulation Maps and Neural Recordingsmentioning

confidence: 74%

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A Neural Basis for Motor Primitives in the Spinal Cord

Hart

Giszter²

2010

J. Neurosci.

244

194

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Motor primitives and modularity may be important in biological movement control. However, their neural basis is not understood. To investigate this, we recorded 302 neurons, making multielectrode recordings in the spinal cord gray of spinalized frogs, at 400, 800, and 1200 m depth, at the L2/L3 segment border. Simultaneous muscle activity recordings were used with independent components analysis to infer premotor drive patterns. Neurons were divided into groups based on motor pattern modulation and sensory responses, depth recorded, and behavior. The 187 motor pattern modulated neurons recorded comprised 14 cutaneous neurons and 28 proprioceptive neurons at 400 m in the dorsal horn, 131 intermediate zone interneurons from ϳ800 m depth without sensory responses, and 14 motoneuron-like neurons at ϳ1200 m. We examined all such neurons during spinal behaviors. Mutual information measures showed that cutaneous neurons and intermediate zone neurons were related better to premotor drives than to individual muscle activity. In contrast, proprioceptive-related neurons and ventral horn neurons divided evenly. For 46 of the intermediate zone interneurons, we found significant postspike facilitation effects on muscle responses using spike-triggered averages representing short-latency postspike facilitations to multiple motor pools. Furthermore, these postspike facilitations matched significantly in both their patterns and strengths with the weighting parameters of individual primitives extracted statistically, although both were initially obtained without reference to one another. Our data show that sets of dedicated interneurons may organize individual spinal primitives. These may be a key to understanding motor development, motor learning, recovery after CNS injury, and evolution of motor behaviors.

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Section: Pattern Generation and Primitive Organization: Spinal Hierarsupporting

confidence: 90%

Section: Spinal Microstimulation Maps and Neural Recordingsmentioning

confidence: 74%

A Neural Basis for Motor Primitives in the Spinal Cord

Hart

Giszter²

2010

J. Neurosci.

244

194

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“…Several kinds of primitives have been suggested (Poppele and Bosco, 2003;Flash and Hochner, 2005;Bizzi et al, 2007;Giszter et al, 2007). We have proposed that fixed-duration bursts or pulses of premotor drive (and associated viscoelastic force fields) are the fundamental execution elements or primitives for spinal movement construction (Giszter et al, 1993(Giszter et al, , 2007Kargo and Giszter, 2000a;Hart and Giszter, 2004). In such bursts, muscles must covary proportionally and synchronously.…”

Section: Introductionmentioning

confidence: 99%

Individual Premotor Drive Pulses, Not Time-Varying Synergies, Are the Units of Adjustment for Limb Trajectories Constructed in Spinal Cord

Kargo¹,

Giszter²

2008

J. Neurosci.

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Complex actions may arise by combining simple motor primitives. Our studies support individual premotor drive pulses or bursts as execution primitives in spinal cord. Alternatively, the fundamental execution primitives at the segmental level could be time-varying synergies. To distinguish these hypotheses, we examined sensory feedback effects during targeted wiping organized in spinal cord. This behavior comprises three bursts. We tested (1) whether feedback altered the structure of individual premotor drive bursts or primitives, and (2) whether feedback differentially modulated different drive bursts or pulses in the three burst sequence. At least two of the three bursts would need to always be comodulated to support a time-varying synergy. We used selective muscle vibration to control spindle feedback from a single muscle (biceps/iliofibularis). The structures of premotor drive bursts were conserved. However, biceps vibration (1) scaled the amplitudes of two bursts coactivated during the initial phase of wiping independently of one another without altering their phase, and (2) independently phase regulated the third burst but preserved its amplitude. Thus, all three bursts were regulated separately. Durations were unaffected. The independent effects depended on (1) time of vibration during wiping, (2) frequency of vibration, and (3) limb configuration. Because each of the three bursts was independently modulated, these data strongly support execution using individual premotor bursts rather than time-varying synergies at the spinal level of motor organization. Our data show that both sensory feedback and central systems of the spinal cord act in concert to adjust the individual premotor bursts in support of the straight and unimodal wiping trajectory.

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“…This usage of the concept of synergy refers to lack of 'selective motor control': children and adults with neurological dysfunction can only use mass movement or stereotyped patterns of movement due to abnormal neurological functioning. Usually, this clinical notion about synergies is underlined by the belief that they reflect a relatively primitive solution to motor coordination, that gets disinhibited or re-expressed when phylogenetically 'newer' neural structures like the cortex are injured 8,9 e.g. following a stroke or cerebral palsy.…”

Section: Motor Synergiesmentioning

confidence: 99%

Motor synergies research in physical therapy: advantages of the uncontrolled manifold approach

Vaz

2017

Fisioter. Pesqui.

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Vaz. Motor synergies research in physical therapy 3 con la teoría y los métodos de análisis de datos del UCM. Se estudian las conexiones entre las actividades de la vida diaria y la formación de sinergias motoras para estabilizar los distintos niveles de rendimiento, así como la distribución de la variabilidad de las sinergias, su fuerza y sus ajustes de anticipación. Tras las intervenciones en la rehabilitación también se deben estudiar cambios en los valores de las sinergias. El UCM es un sólido abordaje científico para informar sobre decisiones clínicas a cerca de la necesidad de deshacer, reequilibrarse, crear o fortalecer las sinergias motoras de los pacientes con trastornos de movimiento.Palabras clave | Destreza Motora; Modalidades de Fisioterapia;Revisión.

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Primitives, premotor drives, and pattern generation: a combined computational and neuroethological perspective

Cited by 81 publications

References 86 publications

A Neural Basis for Motor Primitives in the Spinal Cord

A Neural Basis for Motor Primitives in the Spinal Cord

Individual Premotor Drive Pulses, Not Time-Varying Synergies, Are the Units of Adjustment for Limb Trajectories Constructed in Spinal Cord

Motor synergies research in physical therapy: advantages of the uncontrolled manifold approach

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