Morphology of nerve fibers regenerating through freeze-thawed autogenous skeletal muscle grafts in rats

1990 ◽  
Vol 3 (2) ◽  
pp. 107-119 ◽  
Author(s):  
S. E. Gschmeissner ◽  
J. M. Gattuso ◽  
M. A. Glasby
Keyword(s):  
Skeletal Muscle ◽  
Nerve Fibers

scholarly journals Prion Infection of Skeletal Muscle Cells and Papillae in the Tongue

2004 ◽  
Vol 78 (13) ◽  
pp. 6792-6798 ◽  
Author(s):  
Ellyn R. Mulcahy ◽  
Jason C. Bartz ◽  
Anthony E. Kincaid ◽  
Richard A. Bessen
Keyword(s):  
Skeletal Muscle ◽  
Sensory Nerve ◽  
Meat Products ◽  
Muscle Cells ◽  
Nerve Fibers ◽  
Skeletal Muscle Cells ◽  
Lingual Papillae ◽  
Intracerebral Inoculation ◽  
Axon Terminals ◽  
Prion Infection

ABSTRACT The presence of the prion agent in skeletal muscle is thought to be due to the infection of nerve fibers located within the muscle. We report here that the pathological isoform of the prion protein, PrPSc, accumulates within skeletal muscle cells, in addition to axons, in the tongue of hamsters following intralingual and intracerebral inoculation of the HY strain of the transmissible mink encephalopathy agent. Localization of PrPSc to the neuromuscular junction suggests that this synapse is a site for prion agent spread between motor axon terminals and muscle cells. Following intracerebral inoculation, the majority of PrPSc in the tongue was found in the lamina propria, where it was associated with sensory nerve fibers in the core of the lingual papillae. PrPSc staining was also identified in the stratified squamous epithelium of the lingual mucosa. These findings indicate that prion infection of skeletal muscle cells and the epithelial layer in the tongue can be established following the spread of the prion agent from nerve terminals and/or axons that innervate the tongue. Our data suggest that ingestion of meat products containing prion-infected tongue could result in human exposure to the prion agent, while sloughing of prion-infected epithelial cells at the mucosal surface of the tongue could be a mechanism for prion agent shedding and subsequent prion transmission in animals.

ATP concentrations and muscle tension increase linearly with muscle contraction

2003 ◽  
Vol 95 (2) ◽  
pp. 577-583 ◽  
Author(s):  
Jianhua Li ◽  
Nicholas C. King ◽  
Lawrence I. Sinoway
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Motor Nerve ◽  
Muscle Tension ◽  
Nerve Fibers ◽  
Ventral Root ◽  
Ventral Roots ◽  
Root Stimulation ◽  
Stimulation Of

Previous studies have suggested that activation of ATP-sensitive P2X receptors in skeletal muscle play a role in mediating the exercise pressor reflex (Li J and Sinoway LI. Am J Physiol Heart Circ Physiol 283: H2636–H2643, 2002). To determine the role ATP plays in this reflex, it is necessary to examine whether muscle interstitial ATP (ATPi) concentrations rise with muscle contraction. Accordingly, in this study, muscle contraction was evoked by electrical stimulation of the L7 and S1 ventral roots of the spinal cord in 12 decerebrate cats. Muscle ATPi was collected from microdialysis probes inserted in the muscle. ATP concentrations were determined by the HPLC method. Electrical stimulation of the ventral roots at 3 and 5 Hz increased mean arterial pressure by 13 ± 2 and 16 ± 3 mmHg ( P < 0.05), respectively, and it increased ATP concentration in contracting muscle by 150% ( P < 0.05) and 200% ( P < 0.05), respectively. ATP measured in the opposite control limb did not rise with ventral root stimulation. Section of the L7 and S1 dorsal roots did not affect the ATPi seen with 5-Hz ventral root stimulation. Finally, ventral roots stimulation sufficient to drive motor nerve fibers did not increase ATP in previously paralyzed cats. Thus ATPi is not largely released from sympathetic or motor nerves and does not require an intact afferent reflex pathway. We conclude that ATPi is due to the release of ATP from contracting skeletal muscle cells.

scholarly journals CHOLINESTERASES AND MOTOR END-PLATES IN DEVELOPING DUCK SKELETAL MUSCLE

1965 ◽  
Vol 13 (7) ◽  
pp. 559-565 ◽  
Author(s):  
K. S. KHERA ◽  
Q. N. LAHAM
Keyword(s):  
Skeletal Muscle ◽  
Nerve Fibers ◽  
Diisopropyl Fluorophosphate ◽  
Thigh Muscles ◽  
Motor End Plates ◽  
Subneural Apparatus

End-plates in the thigh muscles of duck embryos were first recognized with myristoylcholine as substrate at the 19th day of incubation. Each appeared as a cholinesterase-positive dot surrounded by a small halo which rapidly increased in size during the 20th and 21st days. The endplates were usually oval in shape, averaging 33 µ x 25 µ with a subneural apparatus 5-12µ wide. The latter contained refringent lamellas arranged transversely in a palisade fashion. From the 21st day to the day of hatching (27-29 days) the number of end-plates progressively increased. After hatching, the myristoylcholine-reacting end-plates were difficult to locate. With acetylthiocholine as substrate, the embryonal end-plates were not demonstrable; however, the posthatched tissues showed numerous end-plates. The nerve trunks and nerve fibers gave a faintly positive myristoylcholine reactions in all stages after the 19th day of incubation. On the basis of the effects of eserine and diisopropyl fluorophosphate, the structures reacting with myristoylcholine and acetylthiocholine contained specific chohinesterase. The end-plates containing nonspecific cholinesterase also appeared on the 19th day of incubation and appeared to increase gradually in number until the 15th postembryonic day; thereafter they seemed to decrease.

scholarly journals CALCIUM INFLUX IN SKELETAL MUSCLE AT REST, DURING ACTIVITY, AND DURING POTASSIUM CONTRACTURE

1959 ◽  
Vol 42 (4) ◽  
pp. 803-815 ◽  
Author(s):  
C. Paul Bianchi ◽  
A. M. Shanes
Keyword(s):  
Skeletal Muscle ◽  
Rana Pipiens ◽  
Calcium Influx ◽  
Nerve Fibers ◽  
Sartorius Muscle ◽  
Potassium Contracture ◽  
Anion Substitution ◽  
Cent Increase ◽  
Fast Twitch ◽  
Passive Influx

Calcium influx in the sartorius muscle of the frog (Rana pipiens) has been estimated from the rate of entry of Ca45. In the unstimulated preparation it is about equal to what has been reported for squid giant axons, but that per impulse is at least 30 times greater than in nerve fibers. The enhanced twitch when NO-2 replaces Cl- in Ringer's is associated with at least a 60 per cent increase in influx during activity, whereas this anion substitution does not affect the passive influx significantly. Calcium entry during potassium contracture is even more markedly augmented than during electrical stimulation, but only at the beginning of the contracture; thus, when a brief Ca45 exposure precedes excess K+ application, C45 uptake is increased three- to fivefold over the controls not subjected to K+, whereas when C45 and K+ are added together, no measurable increase in Ca45 uptake occurs. These findings are in keeping with the brevity of potassium contracture in "fast (twitch)" fibers such as in sartorius muscle.

scholarly journals Selectivity in regeneration of the oculomotor nerve in the cichlid fish, Astronotus ocellatus

Development ◽  
1965 ◽  
Vol 14 (3) ◽  
pp. 307-317
Author(s):  
R. W. Sperry ◽  
H. L. Arora
Keyword(s):  
Skeletal Muscle ◽  
Cichlid Fish ◽  
General Rule ◽  
Nerve Fibers ◽  
Oculomotor Nerve ◽  
General Validity ◽  
Peripheral Innervation ◽  
Wide Range ◽  
Astronotus Ocellatus ◽  
Regenerating Nerve

It has long been considered a general rule for nerve regeneration that the reinnervation of skeletal muscle is nonselective. Regenerating nerve fibers are supposed to reconnect with one skeletal muscle as readily as another according to studies covering a wide range of vertebrates (Weiss, 1937; Weiss & Taylor, 1944; Weiss & Hoag, 1946; Bernstein & Guth, 1961; Guth, 1961, 1962, 1963). Similarly, in embryogenesis proper functional connexions between nerve centers and particular muscles are supposedly attained, not by selective nerve outgrowth but rather through a process of ‘myotypic modulation’ (Weiss, 1955) that presupposes nonselective peripheral innervation. Doubt about the general validity of this rule and the concepts behind it has come from a series of studies on regeneration of the oculomotor nerve in teleosts, urodeles, and anurans and of spinal fin nerves in teleosts (Sperry, 1946, 1947, 1950, 1965; Sperry & Deupree, 1956; Arora & Sperry, 1957a, 1964).

scholarly journals Angiopoietin-1 enhances skeletal muscle regeneration in mice

2015 ◽  
Vol 308 (7) ◽  
pp. R576-R589 ◽  
Author(s):  
Mahroo Mofarrahi ◽  
Joseph M. McClung ◽  
Christopher D. Kontos ◽  
Elaine C. Davis ◽  
Bassman Tappuni ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Capillary Density ◽  
Nerve Fibers ◽  
Skeletal Muscle Regeneration ◽  
Mrna Levels ◽  
Skeletal Myoblasts ◽  
Skeletal Muscle Satellite Cell ◽  
Muscle Progenitor Cell ◽  
Angiopoietin 1

Activation of muscle progenitor cell myogenesis and endothelial cell angiogenesis is critical for the recovery of skeletal muscle from injury. Angiopoietin-1 (Ang-1), a ligand of Tie-2 receptors, enhances angiogenesis and skeletal muscle satellite cell survival; however, its role in skeletal muscle regeneration after injury is unknown. We assessed the effects of Ang-1 on fiber regeneration, myogenesis, and angiogenesis in injured skeletal muscle (tibialis anterior, TA) in mice. We also assessed endogenous Ang-1 levels and localization in intact and injured TA muscles. TA fiber injury was triggered by cardiotoxin injection. Endogenous Ang-1 mRNA levels immediately decreased in response to cardiotoxin then increased during the 2 wk. Ang-1 protein was expressed in satellite cells, both in noninjured and recovering TA muscles. Positive Ang-1 staining was present in blood vessels but not in nerve fibers. Four days after the initiation of injury, injection of adenoviral Ang-1 into injured muscles resulted in significant increases in in situ TA muscle contractility, muscle fiber regeneration, and capillary density. In cultured human skeletal myoblasts, recombinant Ang-1 protein increased survival, proliferation, migration, and differentiation into myotubes. The latter effect was associated with significant upregulation of the expression of the myogenic regulatory factors MyoD and Myogenin and certain genes involved in cell cycle regulation. We conclude that Ang-1 strongly enhances skeletal muscle regeneration in response to fiber injury and that this effect is mediated through induction of the myogenesis program in muscle progenitor cells and the angiogenesis program in endothelial cells.

scholarly journals Geometric Basis of Action Potential of Skeletal Muscle Cells

2021 ◽  
Author(s):  
Qing Li
Keyword(s):  
Skeletal Muscle ◽  
Action Potential ◽  
Synaptic Connection ◽  
Motor Nerve ◽  
Muscle Cells ◽  
Nerve Fibers ◽  
Skeletal Muscle Cells ◽  
Curve Manifold ◽  
Time Curve ◽  
Curved Manifolds

Abstract Although we know something about single cell neuromuscular junction, It is still mysterious how multiple skeletal muscle cells coordinate to complete the intricate spatial curve movement. Here I propose a hypothesis that skeletal muscle cell populations with action potentials are alligned according to a curved manifolds on space(a curved shape on space) and the skeletal muscle also moves according to this corresponding shape(manifolds) when an specific motor nerve impulses are transmitted. the action potential of motor nerve fibers has the characteristics of time curve manifold and this time manifold curve of motor nerve fibers come from visual cortex in which a spatial geometric manifolds are formed within the synaptic connection of neurons. This spatial geometric manifolds of the synaptic connection of neurons orginate from spatial geometric manifolds in outside nature that are transmitted to brain through the cone cells and ganglion cells of the retina.Further,the essence of life is that life is an object that can move autonomously and the essence of life's autonomous movement is the movement of proteins. theoretically, due to the infinite diversity of geometric manifold shapes in nature, the arrangement and combination of 20 amino acids should have infinite diversity, and the geometric manifold formed by protein three-dimensional spatial structure should also have infinite diversity.

Hypothermia and minimal gradient requirements for excitation of cardiac muscle

1961 ◽  
Vol 200 (4) ◽  
pp. 718-722 ◽  
Author(s):  
J. Ushiyama ◽  
C. McC. Brooks
Keyword(s):  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Rectangular Pulse ◽  
Nerve Fibers ◽  
Spinal Neurons ◽  
Long Duration ◽  
Minimal Gradient

A method is described for testing the stimulating-effectiveness of linearly rising current. It was found that cardiac muscle, like nerve fibers, spinal neurons and skeletal muscle has a minimal gradient requirement. Dog trabecular muscles showed great differences in their minimal gradients even at the same temperature but the requirements of individual muscles were rather constant. During hypothermia (24°–27°C) there was a reduction in threshold to stimulation by a rectangular pulse and a great prolongation of the minimal gradient requirement for stimulation as though a type of accommodative reaction present at normal temperatures had been suppressed. Determination of minimal gradient requirements by exponentially rising current gave the same results as obtained with linearly rising currents. Excitation occurred when the rheobasic strengths, as determined by rectangular pulses of long duration, were attained if stimuli satisfied the minimal gradient requirement. The likelihood that a number of accommodative processes occur in tissues subject to stimulatory forces is discussed.

Immunolocalization of GLUT-1 glucose transporter in rat skeletal muscle and in normal and hypoxic cardiac tissue

1993 ◽  
Vol 265 (3) ◽  
pp. E454-E464 ◽  
Author(s):  
C. L. Doria-Medina ◽  
D. D. Lund ◽  
A. Pasley ◽  
A. Sandra ◽  
W. I. Sivitz
Keyword(s):  
Skeletal Muscle ◽  
Cellular Localization ◽  
Glucose Transporter ◽  
Cardiac Tissue ◽  
Heart Tissue ◽  
Nerve Fibers ◽  
Cell Type ◽  
Cardiac Tissues ◽  
Type Distribution ◽  
Glut 1

We compared the expression and cell-type localization of GLUT-1 mRNA and protein between cardiac and skeletal muscle of normal rats. Also, since we recently showed that cardiac GLUT-1 is upregulated in rats exposed to hypobaric hypoxia, we examined the cellular localization of GLUT-1 in cardiac tissue of normal and hypoxic rats. Confocal light microscopy and double immunofluorescent labeling revealed intense localization of GLUT-1 around neurofilament immunoreactivity within gastrocnemius muscle consistent with the previously described localization of large amounts of GLUT-1 in perineurial sheaths of skeletal muscle. However, using the same methods, we were unable to visualize GLUT-1 adjacent to nerve fibers in numerous sections of right or left ventricles or atria. Compared with skeletal myoctes, however, GLUT-1 immunofluorescence among cardiomyocytes was much more intense, particularly along the plasma membrane and especially intercalated discs. GLUT-1 immunofluorescence was also seen within the walls of arterioles within the heart. The predominant localization of GLUT-1 expression to cardiomyocytes in heart tissue was confirmed by in situ mRNA hybridization to digoxigenin-conjugated GLUT-1 cDNA. Northern blot analysis demonstrated that GLUT-1 mRNA was increased severalfold in the cardiac tissues compared with skeletal muscle. Although we detected GLUT-1 protein by immunoblotting of detergent extracts of the heart, we could not detect GLUT-1 in similar extracts of skeletal muscle. The cell type distribution of GLUT-1 in hearts of hypoxic rats was not different by immunohistochemistry from normals. These data indicate that 1) the cell-type distribution of GLUT-1 in the heart differs markedly from that in skeletal muscle. GLUT-1 in cardiac tissue, unlike skeletal muscle, is predominantly expressed within myocytes. 2) Cardiac GLUT-1 is not located along nerve fibers. 3) GLUT-1 mRNA and protein levels in cardiac tissue are considerably greater than in skeletal muscle. 4) The hypoxia-induced increase in cardiac GLUT-1 that we previously reported must occur within cardiomyocytes.

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