[The impulse activity of the motor units of the human soleus muscle in the tonic vibration reflex].
The tonic vibration reflex was evoked in the human soleus muscle, the range of vibration frequencies was 30-180 Hz. The potentials of single motor units (MUs) were picked up. At low frequencies (to 70-80 Hz) the potentials of all MUs under study correlated with vibration stimuli. This showed the existence of ripples in the excitatory inflow to motoneurons. With an increase of the vibration frequency the correlation disappeared. In the voluntarily contracted muscle the correlation was revealed at higher vibration frequencies than in the relaxed muscle. Since the vibration is known to depress monosynaptic reflexes from primary spindle endings, it is suggested that the correlation of motoneuron discharges and vibration stimuli at low vibration frequency is, apparently, a result of the activation of secondary spindle endings which via short synaptic pathways evoked discrete EPSPs in motoneurons.
Person
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Kozhina
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D000200:Action Potentials / Q000502:physiology; D004576:Electromyography; D006801:Humans; D009046:Motor Neurons / Q000502:physiology*; D009129:Muscle Tonus / Q000502:physiology*; D009132:Muscles / Q000502:physiology*; D012026:Reflex, Stretch / Q000502:physiology*; D014732:Vibration
Issledovanie impul'satsii dvigatel'nykh edinits kambalovidnoĭ myshtsy cheloveka pri tonicheskom vibratsionnom reflekse.