Visualization of satellite cells in living muscle fibres of the frog

1980 ◽  
Vol 209 (1177) ◽  
pp. 563-568 ◽  
Keyword(s):  
Electron Microscopy ◽  
Horseradish Peroxidase ◽  
Muscle Fibre ◽  
Satellite Cells ◽  
Light Microscope ◽  
Muscle Cells ◽  
Fibre Axis ◽  
Muscle Fibres ◽  
Single Fibres

Satellite cells were visualized in living muscle fibres of the frog. Single fibres or bundles consisting of a few fibres were isolated after treatment with collagenase, and viewed under the light microscope. Subsequent electron microscopy of identified cells confirmed that they were satellite muscle cells. Under the light microscope, satellite cells appear as fusiform cells, tapering into long fine processes usually orientated parallel to the muscle fibre axis. Horseradish peroxidase injected into the muscle fibre was not transferred to the satellite cells.

Comparative strengths and weaknesses of peroxidase and colloidal gold in pre- and post-embedding immunolabeling techniques

1987 ◽  
Vol 45 ◽  
pp. 1002-1005
Author(s):  
D. R. Abrahamson ◽  
P. L. St.John ◽  
E. W. Perry
Keyword(s):  
Electron Microscopy ◽  
Horseradish Peroxidase ◽  
Light Microscopy ◽  
Colloidal Gold ◽  
Light Microscope ◽  
Ultrastructural Localization ◽  
The Other ◽  
Quantitative Studies ◽  
Dense Suspension ◽  
Antigen Localization

Antibodies coupled to tracers for electron microscopy have been instrumental in the ultrastructural localization of antigens within cells and tissues. Among the most popular tracers are horseradish peroxidase (HRP), an enzyme that yields an osmiophilic reaction product, and colloidal gold, an electron dense suspension of particles. Some advantages of IgG-HRP conjugates are that they are readily synthesized, relatively small, and the immunolabeling obtained in a given experiment can be evaluated in the light microscope. In contrast, colloidal gold conjugates are available in different size ranges and multiple labeling as well as quantitative studies can therefore be undertaken through particle counting. On the other hand, gold conjugates are generally larger than those of HRP but usually can not be visualized with light microscopy. Concern has been raised, however, that HRP reaction product, which is exquisitely sensitive when generated properly, may in some cases distribute to sites distant from the original binding of the conjugate and therefore result in spurious antigen localization.

scholarly journals AN ELECTRON MICROSCOPE STUDY OF THE EMBRYOLOGY OF THE INTERCALATED DISC IN THE HEART OF THE RABBIT

1957 ◽  
Vol 3 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Alan R. Muir
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Cardiac Muscle ◽  
Microscope Study ◽  
Light Microscope ◽  
Electron Microscope Study ◽  
Muscle Cells ◽  
Intercalated Disc ◽  
Adult Cell ◽  
Embryonic Muscle

Prenatal and postnatal cardiac muscle from rabbits has been studied by electron microscopy, after osmium fixation and methacrylate embedding. The observations showed that 1. Cell membranes divide the muscle into cellular units from the youngest embryo which was studied (9½ days after coitus) until the adult state. 2. The embryonic muscle cells contain only one nucleus, whereas the adult cell may be multinucleated. 3. At all stages of development, wherever a myofibrillar axis crosses a cellular boundary, the myofilaments are interrupted by an intercalated disc. 4. With age, increase in size and complexity of the discs render them recognisable by the light microscope.

The Structure and Innervation of the Locomotor Muscles of Salps (Tunicata: Thaliacea)

1973 ◽  
Vol 53 (4) ◽  
pp. 873-883 ◽  
Author(s):  
Q. Bone ◽  
K. P. Ryan
Keyword(s):  
Muscle Fibre ◽  
Light Microscope ◽  
Present Note ◽  
The Body ◽  
Muscle Fibres ◽  
Rhythmic Contraction ◽  
Light Microscope Level ◽  
Careful Observation ◽  
General Arrangement ◽  
Locomotor Muscles

Salps swim by rhythmic contraction of the hoop-like bands of muscle which form a series of incomplete annuli along the body. The histology of these muscle bands was briefly examined by various early workers, such as Dolley (1887) and Knoll (1895), but was little known until Fedele (1932,1938) published the results of his careful investigations of a variety of species. His observations demonstrated the complexity and peculiarity of the muscle fibres forming the bands, which, as he pointed out, are in some respects comparable to those of arthropods in the arrangement of the sarcomeres. In all the species he examined, Fedele found that the muscle fibres were essentially similar in organization: a central granular core containing large nuclei was surrounded on the free borders of the fibre by a layer of myofibrils. However, this general arrangement differed in detail between different species, and Fedele recognized five types of muscle fibre, distinguishing these types upon such criteria as the fibrillar arrangement, and the disposition of the nuclei. In an earlier paper (Fedele, 1925) he had also given very clear figures of the manner in which these muscle fibres were innervated. He found that dis-crete motor end-formations occurred on the surface of the muscle bands, and that these were frequently intercalary, unlike the motor terminations of vertebrates.Fedele's work was based upon very careful observation of living and fixed material at the light microscope level; in the present note, we extend his observations by describing the ultrastructure of these curious protochordate muscle fibres.

Embryonic growth and innervation of rat skeletal muscles. - III. Neural regulation of junctional and extra-junctional acetylcholine receptor clusters

1981 ◽  
Vol 293 (1065) ◽  
pp. 287-314 ◽  
Keyword(s):  
Muscle Fibre ◽  
Nerve Terminal ◽  
Time Course ◽  
Muscle Development ◽  
Muscle Cells ◽  
Diaphragm Muscle ◽  
Muscle Fibres ◽  
The Mean ◽  
Receptor Clusters ◽  
Ach Receptors

The number and distribution of acetylcholine (ACh) receptors on muscle cells was studied during development of normal, paralysed and aneural embryonic rat diaphragm muscles. (i) ACh receptors initially are dispersed over the surface of rat embryo myotubes. At day 15| of gestation junctional receptor clusters (‘J-clusters’) form in a well ordered band across the midline of the diaphragm muscle; these also form in denervated and paralysed muscles. At about day 18 of gestation additional ‘EJ-clusters’ develop to either side of the midpoint of treated muscles. (ii) If a nerve terminal is present, J-clusters increase in length with time. The time course of generation of new endplates calculated from frequency distributions of J-cluster lengths accurately predicts the muscle growth curve established from muscle fibre counts. (iii) The mean length of J-clusters in paralysed muscles was greater than in controls, due to small new-formed clusters failing to appear. In muscles allowed to recover from paralysis the mean length was less, due to a preponderance of small, new-formed clusters. These observations show that development of new endplates, which is thought to reflect the development of new muscle cells, is halted in paralysed muscles, and recovery from paralysis is associated with the generation of many new endplates. (iv) J-clusters appeared, but failed to grow, in aneural muscles. In muscles denervated during the later stages of gestation, analysis of the distribution of J-cluster lengths shows that new clusters failed to appear, and existing clusters showed little or no increase in length after the time of removal of the nerve. (v) EJ-clusters form by aggregation of dispersed receptors, and their mean length increases with time. They do not appear to be stable entities, and are removed within 2 d of recovery from paralysis. In paralysed muscles, with both J-clusters and EJclusters present, only J-clusters attract nerve sprouts or become innervated. (vi) A curve is derived showing development of the total number of synaptic terminals in a muscle. This number increases during days 13-18 of gestation, reaching a peak of about 170 % of the adult value during dl8 and d l9 of gestation. There are two episodes of terminal elimination, one during days 19-21 of gestation, and another about 2 weeks postnatally. During the first postnatal week the number of terminals remains constant at about 140% of the adult number, while the average number of inputs per fibre goes down and the number of muscle fibres increases. (vii) Innervation is essential for muscle development. Motoneurons cannot regulate the number of muscle fibres by requiring a simple one-to-one relation between nerve terminal and muscle fibre, and if their role is regulatory as well as supportive of muscle development then some more complex relationship between nerve terminals and developing myotubes must be postulated.

Muscle growth and development in normal-sex-ratio and all-female diploid and triploid Atlantic salmon

1999 ◽  
Vol 202 (15) ◽  
pp. 1991-2016 ◽  
Author(s):  
I.A. Johnston ◽  
G. Strugnell ◽  
M.L. McCracken ◽  
R. Johnstone
Keyword(s):  
Sex Ratio ◽  
Atlantic Salmon ◽  
Muscle Fibre ◽  
Satellite Cells ◽  
Muscle Growth ◽  
Fibre Diameter ◽  
Muscle Fibres ◽  
Female Fish ◽  
Right Hand ◽  
Triploid Fish

Muscle development and growth were investigated in diploid populations of normal-sex-ratio and all-female Atlantic salmon (Salmo salar L.) and their triploid counterparts produced by high-pressure treatment. Somites were formed at the rate of 6 h-1 in both diploids and triploids at 6 degrees C. The rostral-to-caudal development of myotubes, myofibrils and acetylcholinesterase staining at the myosepta was slightly more advanced in triploid than in diploid fish, although the differences were smaller than among individual families. The c-met receptor tyrosine kinase was used as a molecular marker for the satellite cells involved in postembryonic muscle growth. Satellite cell nuclei comprised 17.5 % of total myonuclei in smolts and they were 24 % more abundant in diploid than in triploid fish. Cells expressing the myogenic regulatory factor myf-6, a marker of satellite cells committed to differentiation, represented 14.8 % of total myonuclei in diploids and 12.5 % in triploids. At ambient temperatures, the number of white muscle fibres in normal-sex-ratio fish increased more than 30-fold between the alevin and smolt stages, and approximately 3.5-fold further during the first year of seawater growth. The rate of muscle fibre recruitment in seawater stages was significantly greater in diploid than in triploid fish, reaching 1162 fibres day-1 and 608 fibres day-1, respectively, in all-female groups 800 days post-hatching. For 42 cm fork-length fish, there were approximately one-third more muscle fibres per myotome in diploid than in triploid groups, 649 878 and 413 619, respectively, for all-female fish. The probability density function of muscle fibre diameters in each fish was estimated using non-parametric smoothing techniques, and the mean densities for diploids (fD) and triploids (fT) were calculated. The peak fibre diameter was approximately 20 (micro)m in all age classes, irrespective of ploidy. Distinct bimodal distributions of muscle fibre diameter were evident in all groups 775 days and 839 days post-hatching, reflecting seasonal cycles of fibre recruitment. fD and fT were compared using a non-parametric bootstrap technique and the reference band representing the null-hypothesis indicated that there was no difference with ploidy. Reference bands for normal-sex-ratio fish at 315 days and 470 days indicated that diploids had a higher percentage of smaller-diameter fibres and that triploid distributions had a thicker right-hand tail. Similar differences in fD and fT of muscle fibre diameters were found for all-female fish, although the statistical evidence was less strong. Reference bands indicated differences in the middle range of the distributions of muscle fibre diameter in fish 620–775 days post-hatch, with triploids having a thicker right-hand tail. Thus, a lower density of satellite cells was associated with reduced rates of fibre recruitment but a compensatory increase in muscle fibre hypertrophy in triploid compared with diploid fish.

Electron microscopy of the glio-vascular organization of the brain of octopus

1969 ◽  
Vol 255 (797) ◽  
pp. 13-32 ◽  
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Blood Vessels ◽  
Light And Electron Microscopy ◽  
Muscle Cells ◽  
Medium Size ◽  
Muscle Fibres ◽  
Special Importance ◽  
Form Complex ◽  
Large Neurons

The glio-vascular organization of the octopus brain has been studied by light and electron microscopy. The structure of the walls of the blood vessels has been described. Two types of neuroglia can be recognized, the fibrous and protoplasmic glia; also enigmatic dark cells. Most blood vessels in the neuropil are surrounded by extracellular zones containing collagen. These zones give off glio-vascular tunnels (strands) that penetrate the neuropil in a complex network. The extracellular zones and tunnels contain in addition to collagen, smooth muscle cells and fibrocytes. Glial processes surround the extracellular zones and incompletely partition them from the neuropil. The small neuronal perikarya have no glial folds around them. The medium-size cells have thin glial sheets or finger processes related to their surfaces, which may indent the cells to form small trophospongia. The large neurons of the suboesophageal lobe have complex glial sheaths interspersed with extracellular channels. Both penetrate the neurons to form complex trophospongia. A new form of extracellular material has been observed in these extracellular channels. The occurrence of trophospongia in vertebrate and invertebrate neurons may be correlated with the absence of dendrites. Special problems discussed include the nature of the trophospongial function, the question of fluid-filled extracellular zones and their possible function as lymph channels, and the presence in some of them of haemocyanin molecules identical with those in the blood vessels. Perhaps of special importance is the observation that the lobes of the octopus brain are permeated with extracellular tunnels containing smooth muscle fibres, but it still needs to be determined whether or not the muscle cells in the tunnels of the neuropil actively contract and massage the neuropil to facilitate metabolic and other exchanges.

Multinucleation during myogenesis of the myotome of Xenopus laevis: a qualitative study

Development ◽  
1987 ◽  
Vol 101 (3) ◽  
pp. 583-590 ◽  
Author(s):  
H. Boudjelida ◽  
L. Muntz
Keyword(s):  
Electron Microscope ◽  
Qualitative Study ◽  
Xenopus Laevis ◽  
Dna Synthesis ◽  
Satellite Cells ◽  
Muscle Cells ◽  
Muscle Fibres ◽  
Large Nucleus ◽  
Ultrastructural Studies

Ultrastructural studies of myogenesis in the myotome of Xenopus laevis reveal that the myotubes developed by stage 33/34 have peripheral myofibrils but are still uninucleate with a single large nucleus. By stage 45, the cytoplasm of the muscle cells is filled with myofibrils and there are many small peripheral nuclei, resulting in multinucleate muscle fibres. With the electron microscope, we have examined myotomes from stages 33/34 to 59 of development and some stages were also investigated by autoradiography. There was no evidence from autoradiographic studies for DNA synthesis in muscle cells, and the increase in the number of myonuclei was accompanied by a decrease in their size. Satellite cells were not seen at the myotube stage but were first seen after the cells had become multinucleate, with many small nuclei close together forming rows. Constrictions were frequently observed in the large single nuclei. It is concluded that division of the myonuclei by amitosis is mainly responsible for the multinucleation that occurs during development of the myotome muscle in Xenopus laevis.

scholarly journals Revealing t-tubules in striated muscle with new optical super-resolution microscopy techniques

2014 ◽  
Vol 25 (1) ◽  
pp. 15 ◽  
Author(s):  
Isuru D. Jayasinghe ◽  
Alexander H. Clowsley ◽  
Michelle Munro ◽  
Yufeng Hou ◽  
David J. Crossman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Single Molecule ◽  
Striated Muscle ◽  
Calcium Signalling ◽  
Super Resolution ◽  
Muscle Cells ◽  
Muscle Fibres ◽  
T Tubules ◽  
Microscopy Techniques

The t-tubular system plays a central role in the synchronisation of calcium signalling and excitation-contraction coupling in most striated muscle cells. Light microscopy has been used for imaging t-tubules for well over 100 years and together with electron microscopy (EM), has revealed the three-dimensional complexities of the t-system topology within cardiomyocytes and skeletal muscle fibres from a range of species. The emerging super-resolution single molecule localisation microscopy (SMLM) techniques are offering a near 10-fold improvement over the resolution of conventional fluorescence light microscopy methods, with the ability to spectrally resolve nanometre scale distributions of multiple molecular targets. In conjunction with the next generation of electron microscopy, SMLM has allowed the visualisation and quantification of intricate t-tubule morphologies within large areas of muscle cells at an unprecedented level of detail. In this paper, we review recent advancements in the t-tubule structural biology with the utility of various microscopy techniques. We outline the technical considerations in adapting SMLM to study t-tubules and its potential to further our understanding of the molecular processes that underlie the sub-micron scale structural alterations observed in a range of muscle pathologies.

Fusimotor innervation in the cat

1970 ◽  
Vol 258 (825) ◽  
pp. 315-346 ◽  
Keyword(s):  
Electron Microscopy ◽  
Muscle Fibre ◽  
High Frequency ◽  
Light And Electron Microscopy ◽  
Spindle Pole ◽  
Muscle Fibres ◽  
Flexor Hallucis Longus ◽  
Spindle Poles ◽  
Fusimotor Innervation ◽  
The Mean

The motor innervation of cat spindles was examined in hindlimb muscles using a variety of techniques employed in light and electron microscopy. Observations were made on teased, silver preparations of 267 spindles sampled from the peroneal, flexor hallucis longus, and soleus muscles, hereafter referred to as the PER /FHL /SOL series. The y innervation . Trail endings are almost invariably present, and innervate both bag and chain muscle fibres. T rail fibres accounted for 64.6 to 74.8 % of the total fusimotor supply to samples of spindle poles in the PER/FHL /SOL series, the m ean num ber of fibres per pole varying from 2.7 to 5.0 in the different muscles, and the mean number of ramifications (areas of synaptic contact) per fibre being 3.7. By contrast, the p 2 innervation of a spindle pole generally consists of a single fibre supplying only one plate. In the above samples p 2 fibres accounted for 4.1 to 28.0% of the total fusimotor supply, and the mean number of fibres per pole varied from 0.3 to 1.2 in the different muscles. Ninety per cent of p 2 plates innervate bag fibres. The α innervation . The structure of p 1 plates as seen in both light and electron microscopy compares very closely with that of extrafusal plates. After nerve section p 1 plates degenerate at the same time as extrafusal plates, being the first of the three types of fusimotor ending to disappear. The frequency of the p x innervation is similar to that of the p 2 innervation. In the same samples of P E R /F H L /S O L spindle poles as above p x fibres accounted for 6.0 to 28.8 % of the total fusimotor supply, the mean number of fibres per pole varying from 0.25 to 2.1 in the different muscles. The majority of p 1 fibres enter a pole to terminate in one plate only. Seventy-five per cent of the plates innervate bag fibres. The three types of fusimotor ending are thus not selectively distributed to the two types of intrafusal muscle fibre. All three types of fusimotor fibre may branch within the spindle so as to innervate both bag and chain fibres. Bag fibres receive both types of plate ending as well as trail endings. Most chain fibres receive trail endings only; the rest receive either a p 1 or a p 2 plate innervation in addition, 25 % of the p 1 and 10% of the p 2 innervation being distributed to chain fibres. The significance of this nonselective innervation is interpreted as indicating that the type of contraction elicited by stimulating a fusimotor fibre depends upon the type of ending initiating it rather than upon the type of muscle fibre executing it. Reasons are given for concluding that the dynamic response is controlled via the p 1 and p 2 plates, and that the static response is controlled by the trail endings. The participation of the a fibres in mammalian fusimotor innervation, previously regarded as a vestigial feature, proved to be widespread in the muscles studied and more prevalent in fast muscles (FHL, peroneus digiti quinti) than slow (soleus). A low frequency of p 1 innervation is offset by a high frequency of p 2 (as in peroneus longus), and vice versa (as in FHL). It is unlikely that collaterals from slow a fibres innervating type B muscle fibres are wholly responsible for the high frequency of the p 1 innervation in FHL, and it is suggested that collaterals may also be derived from fast a fibres innervating type C muscle fibres. The possibility of there being some motor fibres of a conduction velocity and with an exclusively fusimotor distribution is also taken into account.

Aminergic and peptidergic modulation of motor function at an identified neuromuscular junction in Helisoma

1989 ◽  
Vol 142 (1) ◽  
pp. 225-243
Author(s):  
M. J. Zoran ◽  
P. G. Haydon ◽  
P. J. Matthews
Keyword(s):  
Muscle Fibre ◽  
Muscle Cells ◽  
Muscle Contractions ◽  
Interactive Effects ◽  
Muscle Fibres ◽  
Buccal Ganglion ◽  
Motor Pathway ◽  
Peripheral Muscle ◽  
Electrophysiological Studies

Electrophysiological studies suggest that motoneurone B19 in the buccal ganglia of Helisoma makes monosynaptic, cholinergic connections with the supralateral radular tensor (SLT) muscle of the buccal mass. Serotonin (5-HT) and small cardioactive peptide B (SCPB) were found to have peripheral modulatory effects on this motor pathway that are consistent with their previously described central facilitatory effects. Both neurotransmitters, when applied exogenously (10(−6) mol l-1) to isolated buccal ganglion-buccal muscle preparations, potentiated the magnitude of motoneurone B19-evoked muscle contractions (6.3 and 2.7 times, respectively) without affecting excitatory junctional potential (EJP) amplitudes. When applied to single dissociated SLT muscle fibres in cell culture, these modulators had similar effects on acetylcholine (ACh)-evoked muscle fibre shortening, demonstrating that these neuromodulators exert direct actions on the muscle cells. The cardioactive peptide FMRFamide (10(−6) mol l-1), although slightly potentiating muscle contractions in reduced neuromuscular preparations, significantly decreased both ACh-evoked muscle fibre shortening and depolarizing potentials in cultured SLT muscle cells. The differential effects of FMRFamide may, in part, be due to the elimination of interactive effects between multiple neurotransmitters that might exist in semi-intact preparations and in vivo. These results demonstrate that 5-HT, SCPB and FMRFamide in Helisoma can directly modulate the peripheral muscle targets of buccal motoneurones involved in the generation of cyclical feeding behaviour.

Sign in / Sign up

Export Citation Format

Share Document