Reciprocal inhibition between motor neurons of the tibialis anterior and triceps surae in humans
| Autor: | Dario Farina, Robin Diedrichs, Utku Ş. Yavuz, Francesco Negro |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Adult
Male 0301 basic medicine high density EMG reciprocal inhibition single motor unit synaptic distribution Physiology Stimulation Biology 17 Psychology And Cognitive Sciences 03 medical and health sciences 0302 clinical medicine Humans Muscle Skeletal Motor Neurons Leg Neurology & Neurosurgery Electromyography General Neuroscience Peroneal Nerve Reciprocal inhibition Neural Inhibition 11 Medical And Health Sciences Electric Stimulation 030104 developmental biology Transmission (telecommunications) 2023 OA procedure high-density EMG Tibial Nerve Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | Journal of Neurophysiology Journal of neurophysiology, 119(5), 1699-1706. American Physiological Society |
| ISSN: | 1522-1598 0022-3077 |
| Popis: | Motor neurons innervating antagonist muscles receive reciprocal inhibitory afferent inputs to facilitate the joint movement in the two directions. The present study investigates the mutual transmission of reciprocal inhibitory afferent inputs between the tibialis anterior (TA) and triceps surae (soleus and medial gastrocnemius) motor units. We assessed this mutual mechanism in large populations of motor units for building a statistical distribution of the inhibition amplitudes during standardized input to the motor neuron pools to minimize the effect of modulatory pathways. Single motor unit activities were identified using high-density surface electromyography (HDsEMG) recorded from the TA, soleus (Sol), and medial gastrocnemius (GM) muscles during isometric dorsi- and plantarflexion. Reciprocal inhibition on the antagonist muscle was elicited by electrical stimulation of the tibial (TN) or common peroneal nerves (CPN). The probability density distributions of reflex strength for each muscle were estimated to examine the strength of mutual transmission of reciprocal inhibitory input. The results showed that the strength of reciprocal inhibition in the TA motor units was fourfold greater than for the GM and the Sol motor units. This suggests an asymmetric transmission of reciprocal inhibition between ankle extensor and flexor muscles. This asymmetry cannot be explained by differences in motor unit type composition between the investigated muscles since we sampled low-threshold motor units in all cases. Therefore, the differences observed for the strength of inhibition are presumably due to a differential reciprocal spindle afferent input and the relative contribution of nonreciprocal inhibitory pathways. NEW & NOTEWORTHY We investigated the mutual transmission of reciprocal inhibition in large samples of motor units using a standardized input (electrical stimulation) to the motor neurons. The results demonstrated that the disynaptic reciprocal inhibition exerted between ankle flexor and extensor muscles is asymmetric. The functional implication of asymmetric transmission may be associated with the neural strategies of postural control. |
| Databáze: | OpenAIRE |
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