scholarly journals DIRECT CONNECTIONS BETWEEN THE T SYSTEM AND THE SUBNEURAL APPARATUS IN MOUSE NEUROMUSCULAR JUNCTIONS DEMONSTRATED BY LANTHANUM

1970 ◽  
Vol 18 (4) ◽  
pp. 302-304 ◽  
Author(s):  
S. I. ZACKS ◽  
A. SAITO
Keyword(s):  
Neuromuscular Junctions ◽  
Subneural Apparatus ◽  
T System

scholarly journals OBSERVATIONS ON THE FINE STRUCTURE AND CYTOCHEMISTRY OF MOUSE AND HUMAN INTERCOSTAL NEUROMUSCULAR JUNCTIONS

1961 ◽  
Vol 10 (4) ◽  
pp. 517-528 ◽  
Author(s):  
S. I. Zacks ◽  
J. M. Blumberg
Keyword(s):  
Fine Structure ◽  
Neuromuscular Junction ◽  
Neuromuscular Junctions ◽  
Surface Membrane ◽  
Basement Membranes ◽  
Intercostal Muscle ◽  
Motor End Plates ◽  
Thin Plastic ◽  
Subneural Apparatus ◽  
Amorphous Surface

The fine structure of the mouse and human intercostal muscle neuromuscular junction was studied after brief fixation in a new formol-sucrose fixative. This primary formalin fixation was followed by brief postosmication in buffered 1 per cent osmium tetroxide. Muscle blocks were embedded in methacrylate or Epon 812 epoxy resin. Marked similarities between mouse and human motor end-plates were observed. Neuromuscular junctions from both mouse and human intercostal muscle showed synaptic vesicles, primary and secondary synaptic clefts, and layered differentiation of the amorphous surface material (ASM) present on the surface of the Schwann cell plasma membrane and on the muscle surface membrane in the region of the neuromuscular junction. An attempt to stain the ASM with lead was unsuccessful. Observations on thick and thin plastic-embedded sections stained by PAS after diastase digestion showed that the ASM within the subneural apparatus is PAS positive. Alcian blue stained the endoneurium and perineurium of peripheral nerve bundles and portions of the end-plates. The similarity of the PAS-positive ASM to other basement membranes described in other sites is discussed and its possible physiologic significance within the subsynaptic apparatus is considered.

Ultrastructural and histochemical observations in the developing iris musculature in the chick

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 117-127
Author(s):  
Y. Narayanan ◽  
C. H. Narayanan
Keyword(s):  
Ache Activity ◽  
Neuromuscular Junctions ◽  
Cell Loss ◽  
Ciliary Ganglion ◽  
Cell Degeneration ◽  
Synaptic Terminals ◽  
Time Table ◽  
The Relationship ◽  
Massive Cell ◽  
T System

Irises from chick embryos and from 2- and 3-week-old chicks were studied using ultrastructural and histochemical methods in order to clarify the relationship between cell loss in the ciliary ganglion and the establishment of permanent peripheral connections between the ciliary neurons and the iris muscle. The iris muscle undergoes morphological and biochemical differentiation between 11 and 13 days of incubation. This period coincides with the critical period in the development of the ciliary ganglion when massive cell degeneration occurs. During this period, the iris develops typical sarcomeric structure, with AChE activity in the nuclear envelope, Golgi, and the ‘T’ system. At 15 days of incubation AChE activity is found localized in discrete areas on the muscle fiber, forming specific neuromuscular junctions. Between 13 and 15 days of incubation, there is a shift in the localization of AChE activity in the iris muscle, from the sarcoplasmic structures to the junctional membranes. Few synaptic terminals are observed in the iris musculature prior to 11 days of incubation.There is a marked increase in the number of synaptic terminals between 11 and 13 days of incubation which also coincides with the period of cell loss in the ciliary ganglion. The establishment of neuromuscular junctions at 15 days of incubation corresponds with the period when the number of neurons in the ciliary ganglion has attained the adult level. The time table of the events described above, leads us to conclude that during development only those neurons in the ciliary ganglion which make peripheral contacts survive, and only such contacts differentiate into mature neuromuscular junctions on the iris muscle. This will imply that neurons which are doomed to die, although they may send out fibers to the periphery, do not make peripheral contacts before death.

Three-Dimensional Visualization of the T-System of Frog Muscle Using High Voltage Electron Microscopy and a Lanthanum Stain

1977 ◽  
Vol 35 ◽  
pp. 570-571 ◽  
Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Biological Tissues ◽  
High Voltage Electron Microscopy ◽  
Transverse Tubular System ◽  
Peroxidase Reaction ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
T System

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.

The innervation of toad lymph hearts: An ultrastructural study

1992 ◽  
Vol 50 (1) ◽  
pp. 898-899
Author(s):  
A.M. Pucci ◽  
C. Fruschelli ◽  
A. Rebuffat ◽  
M. Guarna ◽  
C. Alessandrini ◽  
...  
Keyword(s):  
Ultrastructural Study ◽  
Neuromuscular Junctions ◽  
Nerve Fibers ◽  
Lack Of Information ◽  
Lymph Heart ◽  
Muscular Pump ◽  
Structure And Ultrastructure ◽  
Heart Wall

Amphibians have paired muscular pump organs, called “lymph heart”, which rhythmically pump back the lymph from the large subcutaneous lymph sacs into the veins. The structure and ultrastructure of these organs is well known but to date there is a lack of information about the innervation of lymph hearts. Therefore has been carried out an ultrastructural study in order to study the distribution of the nerve fibers, and the morphology of the neuromuscular junctions in the lymph heart wall.

The Network Parameters Of The T-System In Frog Muscle Measured With The High Voltage Electron Microscope.

1975 ◽  
Vol 33 ◽  
pp. 550-551 ◽  
Author(s):  
Brenda R. Eisenberg ◽  
Lee D. Peachey
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Voltage ◽  
Sartorius Muscle ◽  
High Voltage Electron Microscopy ◽  
Network Parameters ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
T System

Analysis of the electrical properties of the t-system requires knowledge of the geometry of the t-system network. It is now possible to determine the network parameters experimentally by use of high voltage electron microscopy. The t-system was marked with exogenous peroxidase. Conventional methods of electron microscopy were used to fix and embed the sartorius muscle from four frogs. Transverse slices 0.5-1.0 μm thick were viewed at an accelerating voltage of 1000 kV using the JEM-1000 high voltage electron microscope at Boulder, Colorado and prints at x5000 were used for analysis.The length of a t-branch (t) from node to node (Fig. 1a) was measured with a magnifier; at least 150 t-branches around 30 myofibrils were measured from each frog. The mean length of t is 0.90 ± 0.11 μm and the number of branches per myofibril is 5.4 ± 0.2 (mean ± SD, n = 4 frogs).

Co-Culture of ES Cell-Derived Motor Neurons and Myotubes Show the Formation of Neuromuscular Junctions and Changes in Gene Expression

2006 ◽  
Vol 22 (06) ◽  
Author(s):  
Aleid Ruijs ◽  
Tateki Kubo ◽  
Jae Song ◽  
Milan Ranka ◽  
Mark Randolph ◽  
...  
Keyword(s):  
Gene Expression ◽  
Motor Neurons ◽  
Neuromuscular Junctions ◽  
Es Cell

Immunological mechanisms of chronic liver lesions under the influence of chemicals

2020 ◽  
pp. 536-537
Author(s):  
G. S. Agzamova ◽  
M. M. Abdullaeva
Keyword(s):  
The Body ◽  
Chronic Liver ◽  
Toxic Substances ◽  
Liver Lesions ◽  
Industrial Chemicals ◽  
Toxic Agent ◽  
Chronic Poisoning ◽  
Immunological Mechanisms ◽  
T System

The immunological profile of chronic liver lesions depending on the toxic agent was studied. It was revealed that chronic poisoning by industrial toxic substances causes changes in the functional state of the T-system of immunity, long-term contact with industrial chemicals leads to increased sensitization to autoantigens of the body.

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