Acquisition of a Simple Motor Skill: Task-Dependent Adaptation and Long-Term Changes in the Human Soleus Stretch Reflex

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Abstract

Changing the H-reflex through operant conditioning leads to CNS multi-site plasticity and can affect previously learned skills. In order to further understand the mechanisms of this plasticity, we operantly conditioned the initial (M1) component of the soleus stretch reflex. Unlike the H-reflex, the stretch reflex is affected by fusimotor control, comprises several bursts of activity resulting from temporally dispersed afferent inputs, and may activate spinal motoneurons via several different spinal and supraspinal pathways. Neurologically normal participants completed six baseline sessions and 24 operant conditioning sessions in which they were encouraged to increase (M1up) or decrease (M1down) M1 size. Five of eight M1up participants significantly increased M1; the final M1 size of those 5 participants was 143±15% (mean±SE) of the baseline value. All eight M1down participants significantly decreased M1; their final M1 size was 62±6% of baseline. Similar to the previous H-reflex conditioning studies, conditioned reflex change consisted of within-session task-dependent adaptation and across-session long-term change. Task-dependent adaptation was evident in conditioning session 1 with M1up and by session 4 with M1down. Long-term change was evident by session 10 with M1up and session 16 with M1down. Task-dependent adaptation was greater with M1up than with the previous H-reflex up-conditioning. This may reflect adaptive changes in the muscle spindle sensitivity, which affects the stretch reflex but not the H-reflex. Because the stretch reflex is related to motor function more directly than the H-reflex, M1 conditioning may provide a valuable tool for exploring the functional impact of reflex conditioning and its potential therapeutic applications.

Original languageEnglish
JournalJournal of Neurophysiology
ISSN0022-3077
DOIs
Publication statusE-pub ahead of print - 5 Jun 2019

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H-Reflex
Stretch Reflex
Motor Skills
Operant Conditioning
Muscle Spindles
Classical Conditioning
Motor Neurons
Reflex
Conditioning (Psychology)

Cite this

@article{ae8587ce572c41498ddb23ead6fad82b,
title = "Acquisition of a Simple Motor Skill: Task-Dependent Adaptation and Long-Term Changes in the Human Soleus Stretch Reflex",
abstract = "Changing the H-reflex through operant conditioning leads to CNS multi-site plasticity and can affect previously learned skills. In order to further understand the mechanisms of this plasticity, we operantly conditioned the initial (M1) component of the soleus stretch reflex. Unlike the H-reflex, the stretch reflex is affected by fusimotor control, comprises several bursts of activity resulting from temporally dispersed afferent inputs, and may activate spinal motoneurons via several different spinal and supraspinal pathways. Neurologically normal participants completed six baseline sessions and 24 operant conditioning sessions in which they were encouraged to increase (M1up) or decrease (M1down) M1 size. Five of eight M1up participants significantly increased M1; the final M1 size of those 5 participants was 143±15{\%} (mean±SE) of the baseline value. All eight M1down participants significantly decreased M1; their final M1 size was 62±6{\%} of baseline. Similar to the previous H-reflex conditioning studies, conditioned reflex change consisted of within-session task-dependent adaptation and across-session long-term change. Task-dependent adaptation was evident in conditioning session 1 with M1up and by session 4 with M1down. Long-term change was evident by session 10 with M1up and session 16 with M1down. Task-dependent adaptation was greater with M1up than with the previous H-reflex up-conditioning. This may reflect adaptive changes in the muscle spindle sensitivity, which affects the stretch reflex but not the H-reflex. Because the stretch reflex is related to motor function more directly than the H-reflex, M1 conditioning may provide a valuable tool for exploring the functional impact of reflex conditioning and its potential therapeutic applications.",
author = "Natalie Mrachacz-Kersting and Kersting, {Uwe Gustav} and {de Brito Silva}, Priscila and Yukiko Makihara and Lars Arendt-Nielsen and Thomas Sinkjaer and Thompson, {Aiko K}",
year = "2019",
month = "6",
day = "5",
doi = "10.1152/jn.00211.2019",
language = "English",
journal = "Journal of Neurophysiology",
issn = "0022-3077",
publisher = "American Physiological Society",

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TY - JOUR

T1 - Acquisition of a Simple Motor Skill

T2 - Task-Dependent Adaptation and Long-Term Changes in the Human Soleus Stretch Reflex

AU - Mrachacz-Kersting, Natalie

AU - Kersting, Uwe Gustav

AU - de Brito Silva, Priscila

AU - Makihara, Yukiko

AU - Arendt-Nielsen, Lars

AU - Sinkjaer, Thomas

AU - Thompson, Aiko K

PY - 2019/6/5

Y1 - 2019/6/5

N2 - Changing the H-reflex through operant conditioning leads to CNS multi-site plasticity and can affect previously learned skills. In order to further understand the mechanisms of this plasticity, we operantly conditioned the initial (M1) component of the soleus stretch reflex. Unlike the H-reflex, the stretch reflex is affected by fusimotor control, comprises several bursts of activity resulting from temporally dispersed afferent inputs, and may activate spinal motoneurons via several different spinal and supraspinal pathways. Neurologically normal participants completed six baseline sessions and 24 operant conditioning sessions in which they were encouraged to increase (M1up) or decrease (M1down) M1 size. Five of eight M1up participants significantly increased M1; the final M1 size of those 5 participants was 143±15% (mean±SE) of the baseline value. All eight M1down participants significantly decreased M1; their final M1 size was 62±6% of baseline. Similar to the previous H-reflex conditioning studies, conditioned reflex change consisted of within-session task-dependent adaptation and across-session long-term change. Task-dependent adaptation was evident in conditioning session 1 with M1up and by session 4 with M1down. Long-term change was evident by session 10 with M1up and session 16 with M1down. Task-dependent adaptation was greater with M1up than with the previous H-reflex up-conditioning. This may reflect adaptive changes in the muscle spindle sensitivity, which affects the stretch reflex but not the H-reflex. Because the stretch reflex is related to motor function more directly than the H-reflex, M1 conditioning may provide a valuable tool for exploring the functional impact of reflex conditioning and its potential therapeutic applications.

AB - Changing the H-reflex through operant conditioning leads to CNS multi-site plasticity and can affect previously learned skills. In order to further understand the mechanisms of this plasticity, we operantly conditioned the initial (M1) component of the soleus stretch reflex. Unlike the H-reflex, the stretch reflex is affected by fusimotor control, comprises several bursts of activity resulting from temporally dispersed afferent inputs, and may activate spinal motoneurons via several different spinal and supraspinal pathways. Neurologically normal participants completed six baseline sessions and 24 operant conditioning sessions in which they were encouraged to increase (M1up) or decrease (M1down) M1 size. Five of eight M1up participants significantly increased M1; the final M1 size of those 5 participants was 143±15% (mean±SE) of the baseline value. All eight M1down participants significantly decreased M1; their final M1 size was 62±6% of baseline. Similar to the previous H-reflex conditioning studies, conditioned reflex change consisted of within-session task-dependent adaptation and across-session long-term change. Task-dependent adaptation was evident in conditioning session 1 with M1up and by session 4 with M1down. Long-term change was evident by session 10 with M1up and session 16 with M1down. Task-dependent adaptation was greater with M1up than with the previous H-reflex up-conditioning. This may reflect adaptive changes in the muscle spindle sensitivity, which affects the stretch reflex but not the H-reflex. Because the stretch reflex is related to motor function more directly than the H-reflex, M1 conditioning may provide a valuable tool for exploring the functional impact of reflex conditioning and its potential therapeutic applications.

U2 - 10.1152/jn.00211.2019

DO - 10.1152/jn.00211.2019

M3 - Journal article

JO - Journal of Neurophysiology

JF - Journal of Neurophysiology

SN - 0022-3077

ER -