Biomaterial Database

Presynaptic inhibition compared with homosynaptic depression as an explanation for soleus H-reflex depression in humans. 1997

A F Kohn, and M K Floeter, and M Hallett

National Institutes of Health, NINDS, Human Motor Control Section, USA. andfkohn@leb.usp.br

The H-reflex is depressed for seconds if elicited following a single H-reflex or train of H-reflexes. Presynaptic inhibition from flexor afferents (tibialis anterior) onto soleus Ia afferents elicited by either single or trains of stimuli had no effect on the soleus H-reflex on a time scale of seconds. Postsynaptic inhibition was also excluded by magnetic stimulation tests that showed that the excitability of the motoneuron pool was not changed at latencies within a range of seconds. Homosynaptic depression localized at the presynaptic terminal seems to be the mechanism behind the H-reflex depression in humans.

UI	MeSH Term	Description	Entries
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
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
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
D004574	Electromagnetic Fields	Fields representing the joint interplay of electric and magnetic forces.	Electromagnetic Field,Field, Electromagnetic,Fields, Electromagnetic
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
D006181	H-Reflex	A monosynaptic reflex elicited by stimulating a nerve, particularly the tibial nerve, with an electric shock.	H Reflex,H-Reflexes,H Reflexes,Reflex, H
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
D013569	Synapses	Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.	Synapse
D013979	Tibial Nerve	The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot.	Medial Plantar Nerve,Posterior Tibial Nerve,Medial Plantar Nerves,Nerve, Medial Plantar,Nerve, Posterior Tibial,Nerve, Tibial,Nerves, Medial Plantar,Nerves, Posterior Tibial,Nerves, Tibial,Plantar Nerve, Medial,Plantar Nerves, Medial,Posterior Tibial Nerves,Tibial Nerve, Posterior,Tibial Nerves,Tibial Nerves, Posterior