Inhibitory projection from brachioradialis to biceps brachii motoneurones in human.
Neural projection from the brachioradialis to the biceps brachii motoneurones in human was studied using the method of post-stimulus time histogram. Electrical stimulation to the radial branch innervating the brachioradialis produced inhibition in 11 out of 21 biceps motor units. The central delays of the inhibition were 0.7-1.2 ms longer than those of the homonymous facilitation. The inhibition was evoked with the intensity below the motor threshold. Pure cutaneous stimulation provoked no effects on the motor-unit firing. These findings suggest that group I afferents from the brachioradials mediate an oligosynaptic inhibition of the biceps brachii motoneurones.
Department of Anatomy, Shinshu University School of Medicine, Matsumoto, Japan.
A
A
Naito
M
M
Shindo
T
T
Miyasaka
Y J
YJ
Sun
H
H
Morita
D000328:Adult; D004558:Electric Stimulation; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D006801:Humans; D009046:Motor Neurons / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation*; D009433:Neural Inhibition / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D012016:Reference Values