Biomaterial Database

Human interlimb reflexes evoked by electrical stimulation of cutaneous nerves innervating the hand and foot. 2001

E P Zehr, and D F Collins, and R Chua

Neurophysiology Laboratory, E-401 VVC, Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, T6G 2H9, Canada. pzehr@ualberta.ca

There is some discrepancy over the extent to which reflex pathways from different cutaneous nerves in the hand and foot link the cervical and lumbar spinal cord in neurologically intact humans. The present experiments were designed to determine whether stimulation of a cutaneous nerve in the foot or in the hand evoked reflexes in the non-stimulated limbs (interlimb reflexes). Reflexes were elicited by stimulating (5x1-ms pulses at 300 Hz) the superficial peroneal (SP; innervates the foot dorsum) or superficial radial (SR; innervates the dorsolateral portion of the hand) nerve while subjects (n=10) performed focused contractions of different upper and lower limb muscles. Reflex responses were divided into early (<75 ms), middle (75-120 ms), and late (>120 ms) epochs as determined from averages of 50 sweeps of stimulus-locked electromyographic activity. Significant interlimb reflexes were found at the early latency in 44/106 and 44/103 muscles sampled after SP and SR nerve stimulation, respectively. At the middle latency, significant interlimb reflexes were seen in 89/106 and 87/103 muscles sampled after SP and SR nerve stimulation, respectively. Interlimb reflexes were seen when stimulating at the wrist (i.e. SR nerve) and when stimulating at the ankle (i.e. SP nerve) with an equal probability. The results show that interlimb cutaneous reflexes are widely distributed in humans. The mean latency of the earliest response was quite short and may be mediated by a propriospinal pathway. Functionally, these pathways may provide a substrate for transferring information to coordinate movements between the limb segments.

UI	MeSH Term	Description	Entries
D008159	Lumbar Vertebrae	VERTEBRAE in the region of the lower BACK below the THORACIC VERTEBRAE and above the SACRAL VERTEBRAE.	Vertebrae, Lumbar
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009431	Neural Conduction	The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.	Nerve Conduction,Conduction, Nerve,Conduction, Neural,Conductions, Nerve,Conductions, Neural,Nerve Conductions,Neural Conductions
D010525	Peripheral Nerves	The nerves outside of the brain and spinal cord, including the autonomic, cranial, and spinal nerves. Peripheral nerves contain non-neuronal cells and connective tissue as well as axons. The connective tissue layers include, from the outside to the inside, the epineurium, the perineurium, and the endoneurium.	Endoneurium,Epineurium,Perineurium,Endoneuriums,Epineuriums,Nerve, Peripheral,Nerves, Peripheral,Perineuriums,Peripheral Nerve
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
D002574	Cervical Vertebrae	The first seven VERTEBRAE of the SPINAL COLUMN, which correspond to the VERTEBRAE of the NECK.	Cervical Spine,Cervical Spines,Spine, Cervical,Vertebrae, Cervical
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D004576	Electromyography	Recording of the changes in electric potential of muscle by means of surface or needle electrodes.	Electromyogram,Surface Electromyography,Electromyograms,Electromyographies,Electromyographies, Surface,Electromyography, Surface,Surface Electromyographies
D005528	Foot	The distal extremity of the leg in vertebrates, consisting of the tarsus (ANKLE); METATARSUS; phalanges; and the soft tissues surrounding these bones.	Feet