Operant conditioning of primate triceps surae H-reflex produces reflex asymmetry

1. Study of memory traces in higher animals requires experimental models possessing well-localized and technically accessible memory traces--plasticity responsible for behavioral change, not dependent on control from elsewhere, and open to detailed investigation. Our purpose has been to develop such a model based on the wholly spinal, largely monosynaptic path of the spinal stretch reflex. Previous studies described operant conditioning of this reflex and of its electrical analog, the H-reflex. In this study, we sought to determine whether conditioning causes changes in the spinal cord that affect the reflex and are not dependent on continued supraspinal influence, and thus qualify as memory traces. 2. Sixteen monkeys underwent chronic conditioning of the triceps surae H-reflex. Eight were rewarded for increasing H-reflex amplitude (HR increases mode), and eight were rewarded for decreasing it (HR decreases mode). In each animal, the other leg was an internal control. Over several months of conditioning, H-reflex amplitude in the conditioned leg rose in HR increases animals and fell in HR decreases animals. H-reflex amplitude in the control leg changed little. 3. After HR increases or HR decreases conditioning, each animal was deeply anesthetized and surgically prepared. The reflex response to supramaximal dorsal root stimulation was measured from the triceps surae nerve as percent of response to supramaximal ventral root stimulation, which was the maximum possible response. Data from both legs were collected before and for up to 3 days after thoracic (T9-10) cord transection. The animal remained deeply anesthetized throughout and was killed by overdose. 4. The reflex asymmetries produced by conditioning were still present several days after transection removed supraspinal influence: reflexes of HR increases animals were significantly larger in HR increases legs than in control legs and reflexes of HR decreases animals were significantly smaller in HR decreases legs than in control legs. 5. Reflex amplitude was much greater in the control legs of anesthetized HR decreases animals than in the control legs of anesthetized HR increases animals. 6. Chronic conditioning had at least two effects on the spinal cord. The first effect, task-appropriate reflex asymmetry, was evident both in the awake behaving animal and in the anesthetized transected animal. The second effect, larger control leg reflexes in HR decreases than in HR increases animals, was evident only in the anesthetized animal. By removing supraspinal control, anesthesia and transection revealed a previously hidden effect of conditioning.(ABSTRACT TRUNCATED AT 400 WORDS)

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Operant conditioning of primate spinal reflexes: the H-reflex

Journal of Neurophysiology ◽

10.1152/jn.1987.57.2.443 ◽

1987 ◽

Vol 57 (2) ◽

pp. 443-459 ◽

Cited By ~ 93

Author(s):

J. R. Wolpaw

Keyword(s):

Operant Conditioning ◽

H Reflex ◽

Spinal Reflexes ◽

Triceps Surae ◽

Spinal Reflex ◽

Control Mode ◽

Response Threshold ◽

Reflex Amplitude ◽

Emg Amplitude ◽

Spinal Stretch Reflex

The study of primate memory substrates, the CNS alterations which preserve conditioned responses, requires an experimental model that fulfills two criteria. First, the essential alterations must be in a technically accessible location. Second, they must persist without input from other CNS regions. The spinal cord is the most technically accessible and readily isolated portion of the primate CNS. Recent work has demonstrated that the spinal stretch reflex (SSR), the initial, wholly segmental response to muscle stretch, can be operantly conditioned and suggests that this conditioning may produce persistent spinal alteration. The present study attempted similar operant conditioning of the H-reflex, the electrical analog of the SSR. The primary goals were to demonstrate that spinal reflex conditioning can occur even if the muscle spindle is removed from the reflex arc and to demonstrate conditioning in the lumbosacral cord, which is far preferable to the cervical cord for future studies of neuronal and synaptic mechanisms. Nine monkeys prepared with chronic fine-wire triceps surae (gastrocnemius and soleus) electromyographic (EMG) electrodes were taught by computer to maintain a given level of background EMG activity. At random times, a voltage pulse just above M response (direct muscle response) threshold was delivered to the posterior tibial nerve via a chronically implanted silicon nerve cuff and elicited the triceps surae H-reflex. Under the control mode, reward always followed. Under the HR increases or HR decreases mode, reward followed only if the absolute value of triceps surae EMG from 12 to 22 ms after the pulse (the H-reflex interval) was above (HR increases) or below (HR decreases) a set value. Monkeys completed 3,000-6,000 trials/day over study periods of 2-3 mo. Background EMG and M response amplitude remained stable throughout data collection. H-reflex amplitude remained stable under the control mode. Under the HR increases mode (5 animals) or HR decreases mode (4 animals), H-reflex amplitude (EMG amplitude in the H-reflex interval minus background EMG amplitude) changed appropriately over at least 6 wk. Change appeared to occur in two phases: an abrupt change within the first day, followed by slower change, which continued indefinitely. Change occurred in all three triceps surae muscles (medial and lateral gastrocnemii and soleus). Under the HR increases mode, H-reflex amplitude rose to an average of 213% of control, whereas under the HR decreases mode it fell to an average of 68% of control. The results demonstrate that the H-reflex can be operantly conditioned.(ABSTRACT TRUNCATED AT 400 WORDS)

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Acute Effects of Kinesiology Taping Stretch Tensions on Soleus and Gastrocnemius H-Reflex Modulations

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094411 ◽

2021 ◽

Vol 18 (9) ◽

pp. 4411

Author(s):

Yung-Sheng Chen ◽

Shi Zhou ◽

Zachary J. Crowley-McHattan ◽

Pedro Bezerra ◽

Wei-Chin Tseng ◽

...

Keyword(s):

H Reflex ◽

Triceps Surae ◽

Reflex Modulation ◽

Hoffmann Reflex ◽

Acute Effects ◽

Physically Active ◽

M Wave ◽

Subject Design ◽

Minor Influence ◽

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This study examined the acute effects of stretch tensions of kinesiology taping (KT) on the soleus (SOL), medial (MG), and lateral (LG) gastrocnemius Hoffmann-reflex (H-reflex) modulation in physically active healthy adults. A cross-over within-subject design was used in this study. Twelve physically active collegiate students voluntarily participated in the study (age = 21.3 ± 1.2 years; height = 175.6 ± 7.1 cm; body weight = 69.9 ± 7.1 kg). A standard Y-shape of KT technique was applied to the calf muscles. The KT was controlled in three tension intensities in a randomised order: paper-off, 50%, and 100% of maximal stretch tension of the tape. The peak-to-peak amplitude of maximal M-wave (Mmax) and H-reflex (Hmax) responses in the SOL, MG, and LG muscles were assessed before taping (pre-taping), taping, and after taping (post-taping) phases in the lying prone position. The results demonstrated significantly larger LG Hmax responses in the pre-taping condition than those in the post-taping condition during paper-off KT (p = 0.002). Moreover, the ΔHmax/Mmax of pre- and post-taping in the SOL muscle was significantly larger during 50%KT tension than that of paper-off (p = 0.046). In conclusion, the stretch tension of KT contributes minor influence on the spinal motoneuron excitability in the triceps surae during rest.

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Operant conditioning of primate H-reflex: phases of development

Neuroscience Letters ◽

10.1016/0304-3940(94)90319-0 ◽

1994 ◽

Vol 170 (2) ◽

pp. 203-207 ◽

Cited By ~ 14

Author(s):

Jonathan R. Wolpaw ◽

Dayna M. Maniccia ◽

Timothea Elia

Keyword(s):

Operant Conditioning ◽

H Reflex ◽

Phases Of Development

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Modulation of the Triceps Surae H-Reflex with Training

International Journal of Neuroscience ◽

10.3109/00207459408986011 ◽

1994 ◽

Vol 76 (3-4) ◽

pp. 293-303 ◽

Cited By ~ 55

Author(s):

Mark H. Trimble ◽

David M. Koceja

Keyword(s):

H Reflex ◽

Triceps Surae

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Acquisition of a simple motor skill: task-dependent adaptation and long-term changes in the human soleus stretch reflex

Journal of Neurophysiology ◽

10.1152/jn.00211.2019 ◽

2019 ◽

Vol 122 (1) ◽

pp. 435-446 ◽

Cited By ~ 2

Author(s):

N. Mrachacz-Kersting ◽

U. G. Kersting ◽

P. de Brito Silva ◽

Y. Makihara ◽

L. Arendt-Nielsen ◽

...

Keyword(s):

Operant Conditioning ◽

Stretch Reflex ◽

Conditioning Session ◽

H Reflex ◽

Reflex Change ◽

Reflex Pathways ◽

Term Change ◽

Neurologically Normal ◽

Spinal Stretch Reflex

Changing the H reflex through operant conditioning leads to CNS multisite plasticity and can affect previously learned skills. To further understand the mechanisms of this plasticity, we operantly conditioned the initial component (M1) 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 6 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 five 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 by session 16 with M1down. Task-dependent adaptation was greater with M1up than with the previous H-reflex upconditioning. This may reflect adaptive changes in 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. NEW & NOTEWORTHY Since the activity of stretch reflex pathways contributes to locomotion, changing it through training may improve locomotor rehabilitation in people with CNS disorders. Here we show for the first time that people can change the size of the soleus spinal stretch reflex through operant conditioning. Conditioned stretch reflex change is the sum of task-dependent adaptation and long-term change, consistent with H-reflex conditioning yet different from it in the composition and amount of the two components.

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Breathable, large-area epidermal electronic systems for recording electromyographic activity during operant conditioning of H-reflex

Biosensors and Bioelectronics ◽

10.1016/j.bios.2020.112404 ◽

2020 ◽

Vol 165 ◽

pp. 112404 ◽

Cited By ~ 2

Author(s):

Young-Tae Kwon ◽

James J.S. Norton ◽

Andrew Cutrone ◽

Hyo-Ryoung Lim ◽

Shinjae Kwon ◽

...

Keyword(s):

Operant Conditioning ◽

H Reflex ◽

Electronic Systems ◽

Electromyographic Activity ◽

Large Area

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Spinal and Supraspinal Effects of Long-Term Stimulation of Sensorimotor Cortex in Rats

Journal of Neurophysiology ◽

10.1152/jn.00283.2007 ◽

2007 ◽

Vol 98 (2) ◽

pp. 878-887 ◽

Cited By ~ 7

Author(s):

Xiang Yang Chen ◽

Shreejith Pillai ◽

Yi Chen ◽

Yu Wang ◽

Lu Chen ◽

...

Keyword(s):

Spinal Cord ◽

Operant Conditioning ◽

Sensorimotor Cortex ◽

H Reflex ◽

Freely Moving ◽

Activity Dependent ◽

Spinal Cord Function ◽

The Brain ◽

Stimulation Of

Sensorimotor cortex (SMC) modifies spinal cord reflex function throughout life and is essential for operant conditioning of the H-reflex. To further explore this long-term SMC influence over spinal cord function and its possible clinical uses, we assessed the effect of long-term SMC stimulation on the soleus H-reflex. In freely moving rats, the soleus H-reflex was measured 24 h/day for 12 wk. The soleus background EMG and M response associated with H-reflex elicitation were kept stable throughout. SMC stimulation was delivered in a 20-day-on/20-day-off/20-day-on protocol in which a train of biphasic 1-ms pulses at 25 Hz for 1 s was delivered every 10 s for the on-days. The SMC stimulus was automatically adjusted to maintain a constant descending volley. H-reflex size gradually increased during the 20 on-days, stayed high during the 20 off-days, and rose further during the next 20 on-days. In addition, the SMC stimulus needed to maintain a stable descending volley rose steadily over days. It fell during the 20 off-days and rose again when stimulation resumed. These results suggest that SMC stimulation, like H-reflex operant conditioning, induces activity-dependent plasticity in both the brain and the spinal cord and that the plasticity responsible for the H-reflex increase persists longer after the end of SMC stimulation than that underlying the change in the SMC response to stimulation.

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Effects of muscle action type on corticospinal excitability and triceps surae muscle-tendon mechanics

Journal of Neurophysiology ◽

10.1152/jn.00079.2017 ◽

2018 ◽

Vol 119 (2) ◽

pp. 563-572 ◽

Cited By ~ 4

Author(s):

P. Valadão ◽

S. Kurokawa ◽

T. Finni ◽

J. Avela

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Motor Control ◽

Pennation Angle ◽

H Reflex ◽

Corticospinal Excitability ◽

Triceps Surae ◽

Fascicle Length ◽

The Central Nervous System ◽

Muscle Actions

This study investigated whether the specific motor control strategy reported for eccentric muscle actions is dependent on muscle mechanical behavior. Motor evoked potentials, Hoffman reflex (H-reflex), fascicle length, pennation angle, and fascicle velocity of soleus muscle were compared between isometric and two eccentric conditions. Ten volunteers performed maximal plantarflexion trials in isometric, slow eccentric (25°/s), and fast eccentric (100°/s) conditions, each in a different randomized testing session. H-reflex normalized by the preceding M wave (H/M) was depressed in both eccentric conditions compared with isometric ( P < 0.001), while no differences in fascicle length and pennation angle were found among conditions. Furthermore, although the fast eccentric condition had greater fascicle velocity than slow eccentric ( P = 0.001), there were no differences in H/M. There were no differences in motor evoked potential size between conditions, and silent period was shorter for both eccentric conditions compared with isometric ( P = 0.009). Taken together, the present results corroborate the hypothesis that the central nervous system has an unique activation strategy during eccentric muscle actions and suggest that sensory feedback does not play an important role in modulating these muscle actions. NEW & NOTEWORTHY The present study provides new insight into the motor control of eccentric muscle actions. It was demonstrated that task-dependent corticospinal excitability modulation does not seem to depend on sensory information processing. These findings support the hypothesis that the central nervous system has a unique activation strategy during eccentric muscle actions.

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