A heteronymous group I oligosynaptic reflex from the common peroneal nerve to vastus medialis muscle was compared with a group I homonymous monosynaptic reflex to soleus, using electrical stimulation of peripheral nerve trunks in two groups of healthy men, mean ages 22 and 65 years. The oligosynaptic reflex was still elicitable with age, its magnitude decreasing similarly to the monosynaptic reflex. A further group of older subjects, mean age 75 years, showed similar results. Clearly, the oligosynaptic reflex is not lost with healthy aging. The motor interneuronal pool may at least partially avoid the age-related cell loss of motoneuronal pools, with consequent maintenance of segmental participation for movements such as gait. The slowing of conduction velocities, for these proprioceptive reflex arcs, may reduce the effectiveness of autoregulation of the gait.
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http://dx.doi.org/10.1016/0197-4580(89)90009-2 | DOI Listing |
Sci Rep
November 2024
Retinal Disorder Research Group, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, 15 av. de France, 1004, Lausanne, VD, Switzerland.
Front Neurosci
May 2024
Department of Functioning and Disability, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Japan.
Prepulse inhibition (PPI) is a well-established phenomenon wherein a weak sensory stimulus attenuates the startle reflex triggered by a subsequent strong stimulus. Within the circuit, variations in target responses observed for PPI paradigms represent prepulse-induced excitability changes. However, little is known about the mechanism of PPI.
View Article and Find Full Text PDFWorld Neurosurg
July 2024
Department of Neurosurgery, Tokyo Women Medical University - Adachi Medical Center, Tokyo, Japan.
Background: Blink reflex (BR) is an oligosynaptic reflex that involves the ophthalmic branch of the trigeminal nerve (TN), ipsilateral main sensory and trigeminospinal nuclei, bilateral facial nuclei, and the facial nerves (FNs). Theoretically, as BR tests the function of both TN and FNs simultaneously, it is an ideal tool for monitoring the status of TN and FNs during skull base surgeries. Nevertheless, it has been used only recently in surgeries as the use of anesthesia limits its use.
View Article and Find Full Text PDFExp Brain Res
June 2024
Department of Anatomy and Structural Science, Yamagata University School of Medicine, Yamagata, Japan.
The anterior (DA) and posterior parts of the deltoid (DP) show alternating contraction during shoulder flexion and extension movements. It is expected that an inhibitory spinal reflex between the DA and DP exists. In this study, spinal reflexes between the DA and DP were examined in healthy human subjects using post-stimulus time histogram (PSTH) and electromyogram averaging (EMG-A).
View Article and Find Full Text PDFFront Neurol
October 2022
Translational Neurophysiology Research Unit, IRCCS Mondino Foundation, Pavia, Italy.
Background: Smell and taste disturbances are among the most frequent neurological symptoms in patients with COVID-19. A concomitant impairment of the trigeminal nerve has been suggested in subjects with olfactory dysfunction, although it has not been confirmed with objective measurement techniques. In this study, we explored the trigeminal function and its correlations with clinical features in COVID-19 patients with impaired smell perception using electrophysiological testing.
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