Orbicularis oculi responses to stimulation of nerve afferents from upper and lower limbs in normal humans.
A brief mechanical or electrical stimulus to peripheral nerve afferents from the upper and lower limbs elicited a small and inconsistent EMG response of the orbicularis oculi muscles. This response was facilitated when the stimuli were delivered at fixed leading time intervals, of 45-300 ms, with respect to a supraorbital nerve electrical stimulus. Also, the peripheral nerve stimulus modified the conventional blink reflex responses, inducing facilitation of R1 and inhibition of R2. These results suggest a complex processing of sensory inputs from the face and the limbs at the brainstem, where they are probably integrated in a network of interneurons influencing the excitability of facial motoneurons.
Unitat d'EMG, Hospital Clinic, Barcelona, Spain.
J
J
Valls-Solé
A
A
Cammarota
R
R
Alvarez
M
M
Hallett
D000328:Adult; D001132:Arm / Q000294:innervation / Q000502:physiology*; D004558:Electric Stimulation; D005143:Eyelids / Q000294:innervation / Q000502:physiology*; D006801:Humans; D007395:Interneurons / Q000502:physiology; D007866:Leg / Q000294:innervation / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology; D009132:Muscles / Q000294:innervation / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology*; D010812:Physical Stimulation; D014276:Trigeminal Nerve / Q000502:physiology