Proprioceptive input resets central locomotor rhythm in the spinal cat

@article{Conway2004ProprioceptiveIR,
  title={Proprioceptive input resets central locomotor rhythm in the spinal cat},
  author={Bernard A. Conway and Hans Hultborn and Ole Kiehn},
  journal={Experimental Brain Research},
  year={2004},
  volume={68},
  pages={643-656}
}
SummaryThe reflex regulation of stepping is an important factor in adapting the step cycle to changes in the environment. The present experiments have examined the influence of muscle proprioceptors on centrally generated rhythmic locomotor activity in decerebrate unanesthetized cats with a spinal transection at Th12. Fictive locomotion, recorded as alternating activity in hindlimb flexor and extensor nerves, was induced by administration of nialamide (a monoamine oxidase inhibitor) and L-DOPA… 
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TLDR
The above results suggest that the group I input from extensor muscles is transmitted through the spinal rhythm generator and more particularly, through the extensor “half-centre”.
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TLDR
A computational model of the mammalian spinal cord circuitry incorporating a two‐level central pattern generator (CPG) with separate half‐centre rhythm generator (RG) and pattern formation (PF) networks can be integrated with reflex circuits to reproduce the reorganization of group I reflex pathways occurring during locomotion.
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TLDR
The functional implication of the results of this and previous studies is that input from group Ib afferents during the stance phase of walking acts to inhibit generation of flexor burst activity and to promote extensor activity.
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TLDR
The lumbosacral interneurones located in the intermediate laminae that can be activated by extensor group I afferents during the extension phase are a previously unknown population of interneURones, and may mediate group I‐evoked disynaptic excitation of extensor motoneurones during locomotion.
Parallel reflex pathways from flexor muscle afferents evoking resetting and flexion enhancement during fictive locomotion and scratch in the cat
TLDR
Reflex actions of muscle afferents in hindlimb flexor nerves were examined on ipsilateral motoneurone activity recorded in peripheral nerves during midbrain stimulation‐evoked fictive locomotion and during fictive scratch in decerebrate cats to indicate the existence of parallel spinal reflex pathways.
Voltage-dependent excitation of motoneurones from spinal locomotor centres in the cat
TLDR
It is shown that the excitatory component of the locomotor drive potentials behaves in a voltage-dependent manner, such that its amplitude increases with depolarisation, and this nonlinear increase in excitation contributes to the mechanisms involved in the production of the high rates of repetitive firing of motoneurones typically seen during locomotion, thus ensuring appropriate muscle contraction.
Sartorius muscle afferents influence the amplitude and timing of flexor activity in walking decerebrate cats
TLDR
Results support an earlier speculation that feedback from large afferents from the sartorius muscles has a strong influence on the generation of flexor burst activity in walking cats.
Short-latency crossed inhibitory responses in extensor muscles during locomotion in the cat.
TLDR
Short-latency crossed inhibition in ankle extensors appears to be an integral component of cutaneous reflex pathways in intact cats during locomotion, which could be important in synchronizing EMG bursts in muscles of both legs.
The role of proprioceptive feedback in the regulation and adaptation of locomotor activity.
TLDR
The role of afferent feedback in adapting locomotor activity to transient and more sustained changes in sensory input in reduced and walking cat preparations is reviewed.
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References

SHOWING 1-10 OF 36 REFERENCES
Peripheral control of the cat's step cycle. II. Entrainment of the central pattern generators for locomotion by sinusoidal hip movements during "fictive locomotion.".
TLDR
The motor pattern could be entrained by applying sinusoidal hip movements, even when a very extensive denervation of the leg had been performed leaving only some of the muscles around the hip and the hip joint innervated.
Two identified afferent neurones entrain a central locomotor rhythm generator
TLDR
A mechanism for proprioceptive entrainment in terms of the opposite feedback effects of these two afferents is proposed and the possible role of these effects in the feedback control of locomotion is discussed.
Inhibition of flexor burst generation by loading ankle extensor muscles in walking cats
Phasic gain control of reflexes from the dorsum of the paw during spinal locomotion
Afferent perturbations during "monopodal" swimming movements in the turtle: phase-dependent cutaneous modulation and proprioceptive resetting of the locomotor rhythm
  • P. R. Lennard
  • Biology, Medicine
    The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1985
TLDR
During “monopodal” swimming, cutaneous and extensor muscle-nerve stimulation had similar phase-dependent effects on the swim cycle in progress, which suggests that muscle afferents have direct access to a central timing network which controls the locomotor rhythm.
The effect of DOPA on the spinal cord. 5. Reciprocal organization of pathways transmitting excitatory action to alpha motoneurones of flexors and extensors.
TLDR
The organization of reciprocal innervation at an interneuronal level is discussed in relation to the primary afferent depolarization evoked in Ia afferent terminals after DOPA and to rhythmic alternating movements.
Stumbling corrective reaction: a phase-dependent compensatory reaction during locomotion.
  • H. Forssberg
  • Psychology, Medicine
    Journal of neurophysiology
  • 1979
TLDR
The results demonstrate that intact cats are able to compensate rapidly for unpredicted perturbations and that the reflex pattern and the induced corrective movements are adapted to the locomotor activity so that functionally meaningful movements are evoked in each phase of the step cycle.
Peripheral control of the cat's step cycle. I. Phase dependent effects of ramp-movements of the hip during "fictive locomotion".
TLDR
Acute spinal and curarized cats can generate "fictive locomotor activity" after an i.v. injection of Nialamid followed by 4-AP and L-DOPA, which expresses a potent peripheral modulatory effect on the central pattern generator.
Multisensory control of spinal reflex pathways.
  • A. Lundberg
  • Psychology, Medicine
    Progress in brain research
  • 1979
...
1
2
3
4
...