Lumbar spinal interneuron activity as it relates to rhythmic motor output in the adult, spinal, air-stepping cat

2021 ◽  
Author(s):  
Chantal Marie McMahon
Keyword(s):  
Motor Output ◽  
Rhythmic Motor ◽  
Spinal Interneuron ◽  
Lumbar Spinal ◽  
Interneuron Activity

A modulatory role for oxygen in shaping rhythmic motor output patterns of neuronal networks

2001 ◽  
Vol 128 (3) ◽  
pp. 299-315 ◽  
Author(s):  
Stefan Clemens ◽  
Jean-Charles Massabuau ◽  
Pierre Meyrand ◽  
John Simmers
Keyword(s):  
Neuronal Networks ◽  
Motor Output ◽  
Rhythmic Motor

Moving forward: methodological considerations when assessing corticospinal excitability during rhythmic motor output in humans

2021 ◽  
Author(s):  
Evan J Lockyer ◽  
Christopher T Compton ◽  
Davis A. Forman ◽  
Gregory E. Pearcey ◽  
Duane C Button ◽  
...  
Keyword(s):  
Neural Control ◽  
Human Movement ◽  
Human Locomotion ◽  
Corticospinal Excitability ◽  
Motor Output ◽  
Rhythmic Motor ◽  
Arm Cycling ◽  
Physiological Relevance ◽  
The Many ◽  
Methodological Considerations

The use of transcranial magnetic stimulation to assess the excitability of the central nervous system to further understand the neural control of human movement is expansive. The majority of the work performed to-date has assessed corticospinal excitability either at rest or during relatively simple isometric contractions. The results from this work are not easily extrapolated to rhythmic, dynamic motor outputs given that corticospinal excitability is task-, phase-, intensity-, direction- and muscle-dependent (Power et al. 2018). Assessing corticospinal excitability during rhythmic motor output, however, involves technical challenges that are to be overcome, or at the minimum considered, when attempting to design experiments and interpret the physiological relevance of the results. The purpose of this narrative review is to highlight research examining corticospinal excitability during a rhythmic motor output and importantly, to provide recommendations regarding the many factors that must be considered when designing and interpreting findings from studies that involve limb movement. To do so, the majority of work described herein refers to work performed using arm cycling (arm pedaling or arm cranking) as a model of a rhythmic motor output used to examine the neural control of human locomotion.

Contributions of intrinsic motor neuron properties to the production of rhythmic motor output in the mammalian spinal cord

2000 ◽  
Vol 53 (5) ◽  
pp. 649-659 ◽  
Author(s):  
Ole Kiehn ◽  
Ole Kjaerulff ◽  
Matthew C Tresch ◽  
Ronald M Harris-Warrick
Keyword(s):  
Spinal Cord ◽  
Motor Neuron ◽  
Motor Output ◽  
Rhythmic Motor ◽  
Intrinsic Motor

scholarly journals Pre-synaptic inhibition of afferent feedback in the macaque spinal cord does not modulate with cycles of peripheral oscillations around 10 Hz

2014 ◽  
Author(s):  
Ferran Galán ◽  
Stuart N Baker
Keyword(s):  
Motor Output ◽  
Afferent Feedback ◽  
Feedback Gain ◽  
Synaptic Inhibition ◽  
Antidromic Activation ◽  
Stimulus Interval ◽  
Finger Flexion ◽  
Mean Width ◽  
Spinal Interneuron ◽  
Terminal Excitability

Spinal interneurons are partially phase-locked to physiological tremor around 10Hz. The phase of spinal interneuron activity is approximately opposite to descending drive to motoneurons, leading to partial phase cancellation and tremor reduction. Pre-synaptic inhibition of afferent feedback modulates during voluntary movements, but it is not known whether it tracks more rapid fluctuations in motor output such as during tremor. In this study, dorsal root potentials (DRPs) were recorded from the C8 and T1 roots in two macaque monkeys following intra-spinal micro-stimulation (random inter-stimulus interval 1.5-2.5 s, 30-100?A), whilst the animals performed an index finger flexion task which elicited peripheral oscillations around 10Hz. Forty one responses were identified with latency <5ms; these were narrow (mean width 0.59 ms), and likely resulted from antidromic activation of afferents following stimulation near terminals. Significant modulation during task performance occurred in 16/41 responses, reflecting terminal excitability changes generated by pre-synaptic inhibition (Wall?s excitability test). Stimuli falling during large-amplitude 8-12Hz oscillations in finger acceleration were extracted, and sub-averages of DRPs constructed for stimuli delivered at different oscillation phases. Although some apparent phase-dependent modulation was seen, this was not above the level expected by chance. We conclude that although terminal excitability reflecting pre-synaptic inhibition of afferents modulates over the timescale of a voluntary movement, it does not follow more rapid changes in motor output. This suggests that pre-synaptic inhibition is not part of the spinal systems for tremor reduction described previously, and that it plays a role in overall ? but not moment-by-moment ? regulation of feedback gain.

Antagonistic Effects of Phentolamine and Octopamine on Rhythmic Motor Output of Crayfish Thoracic Ganglia

1999 ◽  
Vol 82 (6) ◽  
pp. 3586-3589 ◽  
Author(s):  
Mark D. Gill ◽  
Peter Skorupski
Keyword(s):  
Motor Neurons ◽  
Opposite Effect ◽  
Motor Output ◽  
Burst Duration ◽  
Cycle Period ◽  
Nerve Activity ◽  
Locomotor Rhythm ◽  
Pharmacological Modulation ◽  
Thoracic Ganglia ◽  
Rhythmic Motor

Spontaneous rhythmic motor output of crayfish thoracic ganglia consists of bursts of activity in antagonistic leg motor neurons (MNs), alternating with a rather slow cycle period (typically ≥20 s). The most common pattern (77% of preparations) consists of long coxal promotor bursts, the duration of which was correlated strongly with cycle period, and relatively short remotor bursts independent of cycle period. Octopamine, at a concentration of 2–30 μM reversibly retarded this rhythm, increasing both cycle period and promotor burst duration. Higher concentrations of octopamine inhibited promotor nerve activity and abolished rhythmic bursting. Phentolamine (10–50 μM) had the opposite effect of decreasing cycle period, mainly by decreasing promotor burst duration. Whereas in the presence of octopamine promotor bursts were lengthened and became even more strongly related to cycle period, phentolamine promoted a more symmetrical rhythm with shorter promotor bursts that were less dependent on cycle period. When octopamine was applied in the presence of phentolamine, there was no significant increase in cycle period or burst duration, although high octopamine concentrations (100 μM) were still capable of inhibiting promotor nerve activity. To our knowledge, pharmacological modulation of a spontaneous locomotor rhythm by an amine antagonist (applied by itself) has not been reported previously. The results raise the testable possibility that phentolamine exerts its modulatory effects by acting as an octopamine antagonist in crayfish thoracic ganglia.

Habituation and sensitization of spinal interneuron activity in acute spinal cat

1969 ◽  
Vol 14 (2) ◽  
pp. 521-525 ◽  
Author(s):  
Philip M. Groves ◽  
Ray DeMarco ◽  
Richard F. Thompson
Keyword(s):  
Spinal Interneuron ◽  
Interneuron Activity
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