The Effects of Two Different Stretching Programs on Balance Control and Motor Neuron Excitability

We examined the effects of training (4d/wk for 6 wks) with static stretching (SS) or contract-relax proprioceptive neuromuscular facilitation (PNF) on static balance time and motor neuron excitability. Static balance time, Hmax/Mmax ratios and H-reflex recovery curves (HRRC) were measured in 28 healthy subjects (SS: n=10, PNF: n=9, control: n=9) before and after training. SS improved static balance time with a trend observed for PNF. Post training, during 150-200-250 msec interstimulus intervals, we observed a reduction in facilitation, but during 500-700-900 msec interstimulus interval; there was an increase in H2/H1 ratio in the PNF group only. Both stretching techniques improved static balance. The Ia afferent inhibitions during the acute exercises were not found after the SS and PNF training programmes. It was concluded that training with contract-relax proprioceptive neuromuscular facilitation may cause some augmentation in supraspinal and postsynaptic inhibition on the motoneuron pool.

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Hyper- and Hypoventilation Affects Spinal Motor Neuron Excitability During Isoflurane Anesthesia

Anesthesia & Analgesia ◽

10.1213/00000539-199808000-00033 ◽

1998 ◽

Vol 87 (2) ◽

pp. 407-410

Author(s):

Henry H. Zhou ◽

Herman Turndorf

Keyword(s):

Motor Neuron ◽

Spinal Motor Neuron ◽

Isoflurane Anesthesia ◽

Spinal Motor ◽

Neuron Excitability ◽

Motor Neuron Excitability

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A genetic manipulation of motor neuron excitability does not alter locomotor output in Drosophila larvae

10.7287/peerj.preprints.469v1 ◽

2014 ◽

Author(s):

Erin C. McKiernan

Keyword(s):

Motor Neuron ◽

Motor Neurons ◽

Motor Behavior ◽

Genetic Manipulation ◽

Motor Output ◽

Membrane Properties ◽

Neuron Excitability ◽

Motor Neuron Excitability ◽

The Face

Motor activity, like that producing locomotion, is generated by networks of neurons. At the last output level of these networks are the motor neurons, which send signals to the muscles, causing them to contract. Current research in motor control is focused on finding out how motor neurons contribute to shaping the timing of motor behaviors. Are motor neurons just passive relayers of the signals they receive? Or, do motor neurons shape the signals before passing them on to the muscles, thereby influencing the timing of the behavior? It is now well accepted that motor neurons have active, intrinsic membrane properties - there are ion channels in the cell membrane that allow motor neurons to respond to input in non-linear and diverse ways. However, few direct tests of the role of motor neuron intrinsic properties in shaping motor behavior have been carried out, and many questions remain about the role of specific ion channel genes in motor neuron function. In this study, two potassium channel transgenes were expressed in Drosophila larvae, causing motor neurons to fire at lower levels of current stimulation and at higher frequencies, thereby increasing excitability. Mosaic animals were created in which some identified motor neurons expressed the transgenes while others did not. Motor output underlying crawling was compared in muscles innervated by control and experimental neurons in the same animals. Counterintuitively, no effect of the transgenic manipulation on motor output was seen. Future experiments are outlined to determine how the larval nervous system produces normal motor output in the face of altered motor neuron excitability.

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Changes of α-Motor Neuron Excitability after Low-Intensity Exercise with Transient Restriction of Blood Flow

Journal of the Korean Society of Physical Medicine ◽

10.13066/kspm.2015.10.1.63 ◽

2015 ◽

Vol 10 (1) ◽

pp. 63-69 ◽

Cited By ~ 2

Author(s):

Jong-Soon Kim

Keyword(s):

Blood Flow ◽

Motor Neuron ◽

Low Intensity ◽

Neuron Excitability ◽

Motor Neuron Excitability ◽

Low Intensity Exercise

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Exercise following immobility increases lower motor neuron excitability: F-wave and H-reflex studies

Neurophysiologie Clinique ◽

10.1016/j.neucli.2021.12.004 ◽

2022 ◽

Author(s):

Mariana Pereira ◽

Michael Swash ◽

Mamede de Carvalho

Keyword(s):

Motor Neuron ◽

H Reflex ◽

Lower Motor Neuron ◽

Neuron Excitability ◽

Motor Neuron Excitability ◽

F Wave

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The Inhibitory Tendon-Evoked Reflex Is Increased in the Torque-Enhanced State Following Active Lengthening Compared to a Purely Isometric Contraction

Brain Sciences ◽

10.3390/brainsci10010013 ◽

2019 ◽

Vol 10 (1) ◽

pp. 13 ◽

Cited By ~ 4

Author(s):

Vincenzo S. Contento ◽

Brian H. Dalton ◽

Geoffrey A. Power

Keyword(s):

Steady State ◽

Motor Neuron ◽

Muscle Length ◽

Intrinsic Property ◽

Current Data ◽

Afferent Feedback ◽

Matching Task ◽

Neuron Excitability ◽

Important Relationship ◽

Motor Neuron Excitability

Residual torque enhancement (rTE) is a history-dependent property of muscle, which results in an increase in steady-state isometric torque production following an active lengthening contraction as compared to a purely isometric (ISO) contraction at the same muscle length and level of activation. Once thought to be only an intrinsic property of muscle, recent evidence during voluntary contractions indicates a neuromechanical coupling between motor neuron excitability and the contractile state of the muscle. However, the mechanism by which this occurs has yet to be elucidated. The purpose of this study was to investigate inhibition arising from tendon-mediated feedback (e.g., Golgi tendon organ; GTO) through tendon electrical stimulation (TStim) in the ISO and rTE states during activation-matching and torque-matching tasks. Fourteen male participants (22 ± 2 years) performed 10 activation-matching contractions at 40% of their maximum tibialis anterior electromyography amplitude (5 ISO/5 rTE) and 10 torque-matching contractions at 40% of their maximum dorsiflexion torque (5 ISO/5 rTE). During both tasks, 10 TStim were delivered during the isometric steady state of all contractions, and the resulting tendon-evoked inhibitory reflexes were averaged and analyzed. Reflex amplitude increased by ~23% in the rTE state compared to the ISO state for the activation-matching task, and no differences were detected for the torque-matching task. The current data indicate an important relationship between afferent feedback in the torque-enhanced state and voluntary control of submaximal contractions. The history-dependent properties of muscle is likely to alter motor neuron excitability through modifications in tension- or torque-mediated afferent feedback arising from the tendon.

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