المؤلفون: Maria I. Behrens, Cecilia Vergara, Beatriz U. Ramirez

المصدر: Muscle & Nerve. 16:935-940

مصطلحات موضوعية: Male, medicine.medical_specialty, Potassium Channels, Physiology, Muscle Relaxation, Electromyography, Biology, Apamin, Axonal Transport, complex mixtures, Rats, Sprague-Dawley, Cellular and Molecular Neuroscience, chemistry.chemical_compound, Physiology (medical), Internal medicine, medicine, Animals, Colchicine, Relaxation (psychology), medicine.diagnostic_test, Muscles, musculoskeletal, neural, and ocular physiology, Skeletal muscle, Biological activity, musculoskeletal system, Myotonia, medicine.disease, Sciatic Nerve, Muscle Denervation, Rats, Receptors, Neurotransmitter, Electrophysiology, Endocrinology, Muscle relaxation, medicine.anatomical_structure, chemistry, Neurology (clinical)

الوصف: A low conductance calcium-activated K+ channel is thought to regulate the rate of firing of several excitable cells. In skeletal muscle the expression of this channel is under nerve control. Previously, we reported that axonal flow blockade of rat nerves, induced by colchicine, caused atransient increase in muscle apamin receptors, determined by 125I-apamin binding to membrane fractions. The increase in apamin receptors was correlated with repetitive discharges resembling myotonic potentials in the electromyogram, that were blockable by apamin. Here we show that the increase in muscle apamin receptors and the alteration of the electromyogram are followed closely by a slowing of the twitch relaxation, that in turn, is decreased by apamin. Furthermore, the presence of myotonic-like alterations in the electromyogram and a slowing of muscle relaxation when muscle apaminreceptors are increased suggests that these channels may participate, amongother factors, in the generation of some kinds of myotonia. © 1993 John Wiley & Sons, Inc.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::957e0ee4f6f76f887c83a34ae451c4f4Test
https://doi.org/10.1002/mus.880160908Test

المؤلفون: Kozo Kurahashi, Irvine G. McQuarrie, Jane M. Jacob, Hiroshi Mitsumoto

المصدر: Muscle & Nerve. 16:542-547

مصطلحات موضوعية: medicine.medical_specialty, Physiology, Hindlimb, Synaptic Transmission, Mice, Mice, Neurologic Mutants, Cellular and Molecular Neuroscience, Physiology (medical), Internal medicine, medicine, Animals, Motor Neuron Disease, Axon, Chemistry, Motor neuron, Sciatic Nerve, Axons, Anterograde axonal transport, medicine.anatomical_structure, Endocrinology, Axoplasmic transport, Neurology (clinical), Sciatic nerve, Wobbler disease, Forelimb, Neuroscience

الوصف: To investigate axonal function in a model of early motor neuron disease, we examined fast and slow components of anterograde axonal transport in the less-affected hindlimb motor neurons of wobbler mice. To study the fast component (FC), we injected tritiated amino acids into the lumbar spinal cord and retrieved the sciatic nerve after 2 or 3 h. The transport distance was the extent of the plateau of labeling; regression analysis indicated that FC was 25% slower in wobbler mice than in unaffected littermates (P < 0.01). To study slow component (SC), [35S] methionine was injected. Transport distances were to the peaks of labeling for structural proteins after 2 or 3 weeks. Rates for each subcomponent (SCa and SCb) were unaffected by wobbler disease. Because the rate of retrograde FC is also unaffected (Mitsumoto et al., Muscle & Nerve 13:121–126, 1990), we conclude that wobbler disease specifically retards anterograde FC in less-affected hindlimb motor neurons, whereas all components of axonal transport are retarded in forelimb motor neurons. © 1993 John Wiley & Soncs, Inc.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3887e5980b0b85bc75d935f1155ca9beTest
https://doi.org/10.1002/mus.880160517Test

المؤلفون: D. R. Tomlinson, Nigel A. Calcutt, G.B. Willars

المصدر: Muscle & Nerve. 11:1206-1210

مصطلحات موضوعية: medicine.medical_specialty, Physiology, Phosphofructokinase-1, Fructose, Biology, Axonal Transport, Choline O-Acetyltransferase, Diabetes Mellitus, Experimental, Mice, Cellular and Molecular Neuroscience, chemistry.chemical_compound, Physiology (medical), Internal medicine, Diabetes mellitus, medicine, Animals, Sorbitol, Axon, medicine.disease, Choline acetyltransferase, Anterograde axonal transport, Mice, Inbred C57BL, Endocrinology, medicine.anatomical_structure, chemistry, Axoplasmic transport, Female, Neurology (clinical), Inositol, Phosphofructokinase

الوصف: This study examined the anterograde axonal transport of activities of the cytoplasmic enzymes choline acetyltransferase and 6-phosphofructokinase in genetically diabetic C57BL/Ks (db/db) mice and their nondiabetic (+/?) littermates. Diabetic mice exhibited marked reductions in the accumulation of both choline acetyltransferase and 6-phosphofructokinase activity against a constriction of the left sciatic nerve (38% and 51% of nondiabetic values, respectively). Enzyme activities per unit length of unconstricted nerve were not different from those of nondiabetic mice. The nerves of diabetic mice did not accumulate measurable amounts of sorbitol or fructose and showed no myo-inositol depletion. Thus this study concludes that, in diabetic mice, the deficits in anterograde axonal transport of these two enzymes do not arise from the accumulation of sorbitol and fructose nor from depletion of nerve free myo-inositol.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::353648886c0d8e28b48a6d4c34c5d84dTest
https://doi.org/10.1002/mus.880111204Test