A Closer Look: Electron Microscopic Insights into Aging Glutamate Synapses in the Prefrontal Association Cortex

Neuroscience ◽  
2018 ◽  
Vol 394 ◽  
pp. 300-302
Author(s):  
Amy F.T. Arnsten
Keyword(s):  
Association Cortex ◽  
Electron Microscopic ◽  
Glutamate Synapses

Distribution of terminals from pedunculopontine tegmental nucleus and synaptic organization in lateralis medialis-suprageniculate nucleus of cat's thalamus: Anterograde tracing, immunohistochemical studies, and quantitative analysis

2000 ◽  
Vol 17 (6) ◽  
pp. 893-904 ◽  
Author(s):  
KAEKO HOSHINO ◽  
YOSHIMITSU Y. KATOH ◽  
WANZHU BAI ◽  
TADAYOSHI KAIYA ◽  
MASAO NORITA
Keyword(s):  
Brain Regions ◽  
Pedunculopontine Tegmental Nucleus ◽  
Association Cortex ◽  
Projection Neurons ◽  
Synaptic Organization ◽  
Electron Microscopic ◽  
Synaptic Contacts ◽  
Tegmental Nucleus ◽  
Visual Association Cortex ◽  
Immunohistochemical Studies

The cat's lateralis medialis-suprageniculate nuclear complex (LM-Sg) in the thalamus receives input from various brain regions such as the superior colliculus, brain stem, and spinal cord, as well as from visual association cortex. In a previous study, we demonstrated that LM-Sg receives cholinergic fibers from the pedunculopontine tegmental nucleus (PPT) and that cholinergic terminals make synaptic contacts with the dendrites of glutamatergic projection neurons and of GABAergic interneurons (Hoshino et al., 1997). In this study, we investigate the distribution and the organization of PPT terminals by means of a combined anterograde tracer (biotinylated dextran amine, BDA) and immunohistochemical methods. When stained by acetylcholinesterase (AChE), the LM-Sg is not uniformly immunoreactive, but rather is patchily labeled and shows a streaming type of reactivity. The tissue content appears high in enzyme activity in AChE-positive zones and is much lighter in activity in AChE-negative zones. We compared the synaptic organization between AChE-positive and AChE-negative portions of the LM-Sg in separate groups of electron-microscopic material: four types of vesicle containing profiles (RS, RL, F1, and PSD) as well as synaptic glomeruli were observed in this nucleus. Among these, the PSD profiles were observed more frequently in AChE-positive portions than in AChE-negative zones. Furthermore, the number of glomeruli was significantly higher in AChE-positive than in AChE-negative zones. Following the injection of BDA into PPT, labeled terminals within LM-Sg were rather more concentrated in the AChE-positive portion. Although the majority of PPT terminals made synaptic contacts with dendrites in the neuropil, a few terminals were involved in the synaptic glomeruli. The present results show that the synaptic organization is distinctly different between the AChE-positive and AChE-negative portions of LM-Sg. These results suggest that the AChE-positive portions of LM-Sg are relatively more involved in integrating information arising from a diverse set of inputs and processing that information within glomeruli in a complex manner than occurs in the AChE-negative portion of LM-Sg.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Electron Microscopic Study of the Epithelium of the Seminal Vesicle of Aging Rats

1974 ◽  
Vol 32 ◽  
pp. 138-139
Author(s):  
V. F. Allison ◽  
G. C. Fink ◽  
G. W. Cearley
Keyword(s):  
Cell Growth ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Seminal Vesicle ◽  
Seminal Vesicles ◽  
Epithelial Layer ◽  
Epithelial Hyperplasia ◽  
Electron Microscopic ◽  
Aging Rats ◽  
Pseudostratified Epithelium

It is well known that epithelial hyperplasia (benign hypertrophy) is common in the aging prostate of dogs and man. In contrast, little evidence is available for abnormal epithelial cell growth in seminal vesicles of aging animals. Recently, enlarged seminal vesicles were reported in senescent mice, however, that enlargement resulted from increased storage of secretion in the lumen and occurred concomitant to epithelial hypoplasia in that species.The present study is concerned with electron microscopic observations of changes occurring in the pseudostratified epithelium of the seminal vescles of aging rats. Special attention is given to certain non-epithelial cells which have entered the epithelial layer.

The Growth of Herpesvirus mulatto in Human Fibroblast

1974 ◽  
Vol 32 ◽  
pp. 244-245
Author(s):  
Glennelle Washington ◽  
Philip P. McGrath ◽  
Peter R. Graze ◽  
Ivor Royston
Keyword(s):  
Rhesus Monkey ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Peripheral Blood ◽  
Human Fibroblast ◽  
Rhesus Monkeys ◽  
Human Fibroblasts ◽  
Electron Microscopic ◽  
Specific Antisera ◽  
Peripheral Blood Leucocytes

Herpes-like viruses were isolated from rhesus monkey peripheral blood leucocytes when co-cultivated with WI-38 cells. The virus was originally designated rhesus leucocyte-associated herpesvirus (LAHV) and subsequently called Herpesvirus mulatta (HVM). The original isolations were from juvenile rhesus monkeys shown to be free of antibody to rhesus cytomegalic virus. The virus could only be propagated in human or simian fibroblasts. Use of specific antisera developed from HVM showed no relationship between this virus and other herpesviruses. An electron microscopic study was undertaken to determine the morphology of Herpesvirus mulatta (HVM) in infected human fibroblasts.

Observation of biological macromolecules using various electron microscopic methods

1978 ◽  
Vol 36 (2) ◽  
pp. 170-171
Author(s):  
Mitsuo Ohtsuki ◽  
Michael Sogard
Keyword(s):  
Electron Microscope ◽  
Phase Contrast ◽  
Image Interpretation ◽  
Density Lipoprotein ◽  
Biological Macromolecules ◽  
Contrast Effects ◽  
Biological Structure ◽  
Electron Microscopic ◽  
Structural Investigations ◽  
Staining Techniques

Structural investigations of biological macromolecules commonly employ CTEM with negative staining techniques. Difficulties in valid image interpretation arise, however, due to problems such as variability in thickness and degree of penetration of the staining agent, noise from the supporting film, and artifacts from defocus phase contrast effects. In order to determine the effects of these variables on biological structure, as seen by the electron microscope, negative stained macromolecules of high density lipoprotein-3 (HDL3) from human serum were analyzed with both CTEM and STEM, and results were then compared with CTEM micrographs of freeze-etched HDL3. In addition, we altered the structure of this molecule by digesting away its phospholipid component with phospholipase A2 and look for consistent changes in structure.

Localization of immunolabels by electron microscopy and image averaging

1983 ◽  
Vol 41 ◽  
pp. 282-283
Author(s):  
J. Frank ◽  
P.-Y. Sizaret ◽  
A. Verschoor ◽  
J. Lamy
Keyword(s):  
Electron Microscopy ◽  
Single Particle ◽  
Attachment Site ◽  
Uranyl Acetate ◽  
Limulus Polyphemus ◽  
Resolution Limit ◽  
Electron Microscopic ◽  
Image Averaging ◽  
Top View ◽  
Better Than

The accuracy with which the attachment site of immunolabels bound to macromolecules may be localized in electron microscopic images can be considerably improved by using single particle averaging. The example studied in this work showed that the accuracy may be better than the resolution limit imposed by negative staining (∽2nm).The structure used for this demonstration was a halfmolecule of Limulus polyphemus (LP) hemocyanin, consisting of 24 subunits grouped into four hexamers. The top view of this structure was previously studied by image averaging and correspondence analysis. It was found to vary according to the flip or flop position of the molecule, and to the stain imbalance between diagonally opposed hexamers (“rocking effect”). These findings have recently been incorporated into a model of the full 8 × 6 molecule.LP hemocyanin contains eight different polypeptides, and antibodies specific for one, LP II, were used. Uranyl acetate was used as stain. A total of 58 molecule images (29 unlabelled, 29 labelled with antl-LPII Fab) showing the top view were digitized in the microdensitometer with a sampling distance of 50μ corresponding to 6.25nm.

Silver Staining of Pancreatic Islets as Revealed by Electron Microscopy

1967 ◽  
Vol 25 ◽  
pp. 44-45
Author(s):  
Kazuaki Misugi ◽  
Nobuko Misugi ◽  
Hiroshi Yamada
Keyword(s):  
Pancreatic Islet ◽  
Silver Staining ◽  
Islet Cells ◽  
Severe Hypoglycemia ◽  
Granular Cell ◽  
Electron Microscopic Level ◽  
Staining Reaction ◽  
Electron Microscopic ◽  
Pancreatic Islet Cell ◽  
D Cell

The authors had described the fine structure of a type of pancreatic islet cell, which appeared different from typical alpha and beta cells, and tentatively considered that this third type of granular cell probably represents the D cell (Figure 1).Since silver staining has been widely used to differentiate different types of pancreatic islet cells by light microscopy, an attempt to examine this staining reaction at the electron microscopic level was made.Material and Method: Surgically removed specimens from three infants who suffered from severe hypoglycemia were used. The specimens were fixed and preserved in 20% neutral formalin. Frozen sections, 30 to 40 micron thick, were prepared and they were stained by Bielschowsky's method as modified by Suzuki (2). The stained sections were examined under a microscope and islet tissues were isolated. They were fixed in 1% osmium tetroxide in phosphate buffer for one hour and embedded in Epon 812 following dehydration through a series of alcohols and propylene oxide.

Preparatory Procedures for Electron Microscopic Analysis at the Molecular Level of Resolution

1978 ◽  
Vol 36 (3) ◽  
pp. 516-520
Author(s):  
F.J. Sjostrand
Keyword(s):  
Electron Microscope ◽  
Molecular Level ◽  
Microscopic Analysis ◽  
Resolving Power ◽  
Cellular Structures ◽  
Electron Microscopic ◽  
Systematic Analysis ◽  
Technical Developments ◽  
Thin Sectioning ◽  
Obvious Reason

In the 1940's and 1950's electron microscopy conferences were attended with everybody interested in learning about the latest technical developments for one very obvious reason. There was the electron microscope with its outstanding performance but nobody could make very much use of it because we were lacking proper techniques to prepare biological specimens. The development of the thin sectioning technique with its perfectioning in 1952 changed the situation and systematic analysis of the structure of cells could now be pursued. Since then electron microscopists have in general become satisfied with the level of resolution at which cellular structures can be analyzed when applying this technique. There has been little interest in trying to push the limit of resolution closer to that determined by the resolving power of the electron microscope.

A simplified method of emulsion coating and development for quantitative electron microscopic radioautography

1978 ◽  
Vol 36 (2) ◽  
pp. 64-65
Author(s):  
K. Yoshida ◽  
F. Murata ◽  
S. Ohno ◽  
T. Nagata
Keyword(s):  
Mass Production ◽  
Identical Condition ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Simplified Method ◽  
Complicated Process ◽  
Critical Problems ◽  
Electron Microscopic Radioautography ◽  
Quantitative Radioautography

IntroductionSeveral methods of mounting emulsion for radioautography at the electron microscopic level have been reported. From the viewpoint of quantitative radioautography, however, there are many critical problems in the procedure to produce radioautographs. For example, it is necessary to apply and develop emulsions in several experimental groups under an identical condition. Moreover, it is necessary to treat a lot of grids at the same time in the dark room for statistical analysis. Since the complicated process and technical difficulties in these procedures are inadequate to conduct a quantitative analysis of many radioautographs at once, many factors may bring about unexpected results. In order to improve these complicated procedures, a simplified dropping method for mass production of radioautographs under an identical condition was previously reported. However, this procedure was not completely satisfactory from the viewpoint of emulsion homogeneity. This paper reports another improved procedure employing wire loops.

Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

1978 ◽  
Vol 36 (2) ◽  
pp. 46-47
Author(s):  
Jan Zarzycki ◽  
Joseph Szroeder
Keyword(s):  
Mammary Gland ◽  
Protein Denaturation ◽  
Chemical Constituents ◽  
Freeze Substitution ◽  
Electron Microscopic Examination ◽  
Mouse Mammary Gland ◽  
Electron Microscopic ◽  
Preparation Methods ◽  
Microscopic Studies ◽  
Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

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