Biomaterial Database

Refractory period of single motor nerve fibres in man. 1984

J Borg

Electromyographic single motor unit recordings were used to study the axonal refractory period of 28 accessory nerve innervated motor units in young normal subjects and 10 reinnervated motor units in elderly subjects. The refractory period was measured after a conditioning antidromic propagated nerve impulse and after a conditioning electrical nerve stimulus delivered through the same electrode as the test stimulus. The refractory period after a propagated impulse was 1.83 +/- 0.26 ms when test stimulus strength was 10% above the axonal threshold at rest and 0.88 +/- 0.26 ms when test stimulus strength was 100% above threshold. Corresponding data after an electrical stimulus were 2.38 +/- 0.32 ms and 1.28 +/- 0.22 ms. The difference between the methods was partially due to the effect of stimulus spread when the refractory period was measured after an antidromic propagated nerve impulse. Different properties of the nerve fibre membrane and the surrounding tissues after a propagated nerve impulse and after an electrical stimulus might also contribute. For further studies of motor unit pathology both methods seem equally reliable when proper normal data are available.

UI	MeSH Term	Description	Entries
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009412	Nerve Fibers	Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.	Cerebellar Mossy Fibers,Mossy Fibers, Cerebellar,Cerebellar Mossy Fiber,Mossy Fiber, Cerebellar,Nerve Fiber
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
D010543	Peroneal Nerve	The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot.	Fibular Nerve,Fibular Nerves,Nerve, Fibular,Nerve, Peroneal,Nerves, Fibular,Nerves, Peroneal,Peroneal Nerves
D012032	Refractory Period, Electrophysiological	The period of time following the triggering of an ACTION POTENTIAL when the CELL MEMBRANE has changed to an unexcitable state and is gradually restored to the resting (excitable) state. During the absolute refractory period no other stimulus can trigger a response. This is followed by the relative refractory period during which the cell gradually becomes more excitable and the stronger impulse that is required to illicit a response gradually lessens to that required during the resting state.	Period, Neurologic Refractory,Periods, Neurologic Refractory,Refractory Period, Neurologic,Tetanic Fade,Vvedenskii Inhibition,Wedensky Inhibition,Inhibition, Vvedenskii,Inhibition, Wedensky,Neurologic Refractory Period,Neurologic Refractory Periods,Neuromuscular Fade,Neuromuscular Transmission Fade,Refractory Period, Neurological,Refractory Periods, Neurologic,Electrophysiological Refractory Period,Electrophysiological Refractory Periods,Fade, Neuromuscular,Fade, Neuromuscular Transmission,Fade, Tetanic,Neurological Refractory Period,Neurological Refractory Periods,Refractory Periods, Electrophysiological,Refractory Periods, Neurological,Transmission Fade, Neuromuscular
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
D005071	Evoked Potentials	Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.	Event Related Potential,Event-Related Potentials,Evoked Potential,N100 Evoked Potential,P50 Evoked Potential,N1 Wave,N100 Evoked Potentials,N2 Wave,N200 Evoked Potentials,N3 Wave,N300 Evoked Potentials,N4 Wave,N400 Evoked Potentials,P2 Wave,P200 Evoked Potentials,P50 Evoked Potentials,P50 Wave,P600 Evoked Potentials,Potentials, Event-Related,Event Related Potentials,Event-Related Potential,Evoked Potential, N100,Evoked Potential, N200,Evoked Potential, N300,Evoked Potential, N400,Evoked Potential, P200,Evoked Potential, P50,Evoked Potential, P600,Evoked Potentials, N100,Evoked Potentials, N200,Evoked Potentials, N300,Evoked Potentials, N400,Evoked Potentials, P200,Evoked Potentials, P50,Evoked Potentials, P600,N1 Waves,N2 Waves,N200 Evoked Potential,N3 Waves,N300 Evoked Potential,N4 Waves,N400 Evoked Potential,P2 Waves,P200 Evoked Potential,P50 Waves,P600 Evoked Potential,Potential, Event Related,Potential, Event-Related,Potential, Evoked,Potentials, Event Related,Potentials, Evoked,Potentials, N400 Evoked,Related Potential, Event,Related Potentials, Event,Wave, N1,Wave, N2,Wave, N3,Wave, N4,Wave, P2,Wave, P50,Waves, N1,Waves, N2,Waves, N3,Waves, N4,Waves, P2,Waves, P50
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults