Positioning Errors in Simple Targeted Movements of the Forearm Realized in the Absence of Visual Control: Effects of Vibrational Stimulation of Antagonist Muscles

We report neck muscle activity and head movements evoked by electrical stimulation of the superior colliculus (SC) in head-unrestrained monkeys. Recording neck electromyography (EMG) circumvents complications arising from the head's inertia and the kinetics of muscle force generation and allows precise assessment of the neuromuscular drive to the head plant. This study served two main purposes. First, we sought to test the predictions made in the companion paper of a parallel drive from the SC onto neck muscles. Low-current, long-duration stimulation evoked both neck EMG responses and head movements either without or prior to gaze shifts, testifying to a SC drive to neck muscles that is independent of gaze-shift initiation. However, gaze-shift initiation was linked to a transient additional EMG response and head acceleration, confirming the presence of a SC drive to neck muscles that is dependent on gaze-shift initiation. We forward a conceptual neural architecture and suggest that this parallel drive provides the oculomotor system with the flexibility to orient the eyes and head independently or together, depending on the behavioral context. Second, we compared the EMG responses evoked by SC stimulation to those that accompanied volitional head movements. We found characteristic features in the underlying pattern of evoked neck EMG that were not observed during volitional head movements in spite of the seemingly natural kinematics of evoked head movements. These features included reciprocal patterning of EMG activity on the agonist and antagonist muscles during stimulation, a poststimulation increase in the activity of antagonist muscles, and synchronously evoked responses on agonist and antagonist muscles regardless of initial horizontal head position. These results demonstrate that the electrically evoked SC drive to the head cannot be considered as a neural replicate of the SC drive during volitional head movements and place important new constraints on the interpretation of electrically evoked head movements.

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Cycling Exercise with Electrical Stimulation of Antagonist Muscles Increases Plasma Growth Hormone and IL-6

The Tohoku Journal of Experimental Medicine ◽

10.1620/tjem.237.209 ◽

2015 ◽

Vol 237 (3) ◽

pp. 209-217 ◽

Cited By ~ 4

Author(s):

Masayuki Omoto ◽

Hiroo Matsuse ◽

Ryuki Hashida ◽

Yoshio Takano ◽

Shin Yamada ◽

...

Keyword(s):

Growth Hormone ◽

Electrical Stimulation ◽

Plasma Growth Hormone ◽

Cycling Exercise ◽

Antagonist Muscles ◽

Stimulation Of

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Effect of electrical stimulation of antagonist muscles for voluntary motor drive

Somatosensory & Motor Research ◽

10.1080/08990220.2019.1615426 ◽

2019 ◽

Vol 36 (2) ◽

pp. 109-115

Author(s):

Kenichi Sugawara ◽

Shigeo Tanabe ◽

Tomotaka Suzuki ◽

Toshio Higashi

Keyword(s):

Electrical Stimulation ◽

Motor Drive ◽

Voluntary Motor ◽

Antagonist Muscles ◽

Stimulation Of

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Cathodal transcranial direct current stimulation of the primary motor cortex improves selective muscle activation in the ipsilateral arm

Journal of Neurophysiology ◽

10.1152/jn.00171.2011 ◽

2011 ◽

Vol 105 (6) ◽

pp. 2937-2942 ◽

Cited By ~ 30

Author(s):

Alana B. McCambridge ◽

Lynley V. Bradnam ◽

Cathy M. Stinear ◽

Winston D. Byblow

Keyword(s):

Motor Cortex ◽

Upper Limb ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Muscle Activation ◽

Primary Motor Cortex ◽

Selectivity Ratio ◽

Direct Current Stimulation ◽

Antagonist Muscles ◽

Stimulation Of

Proximal upper limb muscles are represented bilaterally in primary motor cortex. Goal-directed upper limb movement requires precise control of proximal and distal agonist and antagonist muscles. Failure to suppress antagonist muscles can lead to abnormal movement patterns, such as those commonly experienced in the proximal upper limb after stroke. We examined whether noninvasive brain stimulation of primary motor cortex could be used to improve selective control of the ipsilateral proximal upper limb. Thirteen healthy participants performed isometric left elbow flexion by contracting biceps brachii (BB; agonist) and left forearm pronation (BB antagonist) before and after 20 min of cathodal transcranial direct current stimulation (c-tDCS) or sham tDCS of left M1. During the tasks, motor evoked potentials (MEPs) in left BB were acquired using single-pulse transcranial magnetic stimulation of right M1 150–270 ms before muscle contraction. As expected, left BB MEPs were facilitated before flexion and suppressed before pronation. After c-tDCS, left BB MEP amplitudes were reduced compared with sham stimulation, before pronation but not flexion, indicating that c-tDCS enhanced selective muscle activation of the ipsilateral BB in a task-specific manner. The potential for c-tDCS to improve BB antagonist control correlated with BB MEP amplitude for pronation relative to flexion, expressed as a selectivity ratio. This is the first demonstration that selective muscle activation in the proximal upper limb can be improved after c-tDCS of ipsilateral M1 and that the benefits of c-tDCS for selective muscle activation may be most effective in cases where activation strategies are already suboptimal. These findings may have relevance for the use of tDCS in rehabilitation after stroke.

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Selective Stimulation of Cat Sciatic Nerve Using an Array of Varying-Length Microelectrodes

Journal of Neurophysiology ◽

10.1152/jn.2001.85.4.1585 ◽

2001 ◽

Vol 85 (4) ◽

pp. 1585-1594 ◽

Cited By ~ 228

Author(s):

Almut Branner ◽

Richard B. Stein ◽

Richard A. Normann

Keyword(s):

Sciatic Nerve ◽

Spinal Cord Injuries ◽

Electrode Array ◽

Selective Stimulation ◽

System A ◽

Antagonist Muscles ◽

Cuff Electrodes ◽

Varying Length ◽

Muscle Groups ◽

Stimulation Of

Restoration of motor function to individuals who have had spinal cord injuries or stroke has been hampered by the lack of an interface to the peripheral nervous system. A suitable interface should provide selective stimulation of a large number of individual muscle groups with graded recruitment of force. We have developed a new neural interface, the Utah Slanted Electrode Array (USEA), that was designed to be implanted into peripheral nerves. Its goal is to provide such an interface that could be useful in rehabilitation as well as neuroscience applications. In this study, the stimulation capabilities of the USEA were evaluated in acute experiments in cat sciatic nerve. The recruitment properties and the selectivity of stimulation were examined by determining the target muscles excited by stimulation via each of the 100 electrodes in the array and using force transducers to record the force produced in these muscles. It is shown in the results that groups of up to 15 electrodes were inserted into individual fascicles. Stimulation slightly above threshold was selective to one muscle group for most individual electrodes. At higher currents, co-activation of agonist but not antagonist muscles was observed in some instances. Recruitment curves for the electrode array were broader with twitch thresholds starting at much lower currents than for cuff electrodes. In these experiments, it is also shown that certain combinations of electrode pairs, inserted into an individual fascicle, excite fiber populations with substantial overlap, whereas other pairs appear to address independent populations. We conclude that the USEA permits more selective stimulation at much lower current intensities with more graded recruitment of individual muscles than is achieved by conventional cuff electrodes.

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Trains of Epidural DC Stimulation of the Cerebellum Tune Corticomotor Excitability

Neural Plasticity ◽

10.1155/2013/613197 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 23

Author(s):

Nordeyn Oulad Ben Taib ◽

Mario Manto

Keyword(s):

Spinal Cord ◽

Motor Cortex ◽

Spatial Representation ◽

Primary Motor Cortex ◽

Anterior Horn ◽

Adult Rats ◽

Afferent Inhibition ◽

Antagonist Muscles ◽

Conditioned Motor ◽

Stimulation Of

We assessed the effects of anodal/cathodal direct current stimulation (DCS) applied epidurally over the cerebellum. We studied the excitability of both the motor cortex and the anterior horn of the spinal cord in adult rats under continuous anesthesia. We also investigated the effects on the spatial representation of a couple of agonist/antagonist muscles on primary motor cortex. Moreover, we evaluated the effects on the afferent inhibition in a paradigm of conditioned corticomotor responses. Anodal DCS of the cerebellum (1) decreased the excitability of the motor cortex, (2) reduced the excitability ofFwaves, as shown by the decrease of both meanF/meanMratios and persistence ofFwaves, (3) exerted a “smoothing effect” on corticomotor maps, reshaping the representation of muscles on the motor cortex, and (4) enhanced the afferent inhibition of conditioned motor evoked responses. Cathodal DCS of the cerebellum exerted partially reverse effects. DCS of the cerebellum modulates the excitability of both motor cortex and spinal cord at the level of the anterior horn. This is the first demonstration that cerebellar DCS tunes the shape of corticomotor maps. Our findings provide a novel mechanism by which DCS of the cerebellum exerts a remote neuromodulatory effect upon motor cortex.

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