scholarly journals Electron probe x-ray microanalysis of small granulated cells in rat sympathetic ganglia after sequential aldehyde and dichromate treatment.

1977 ◽  
Vol 25 (4) ◽  
pp. 275-279 ◽  
Author(s):  
J D Lever ◽  
R M Santer ◽  
K S Lu ◽  
R Presley
Keyword(s):  
Adrenal Medulla ◽  
Electron Probe ◽  
Potassium Dichromate ◽  
Cell Types ◽  
Sympathetic Ganglia ◽  
Type Ii ◽  
Treatment Sequence ◽  
X Ray ◽  
Small Granulated Cells

Rat adrenal medulla and celiac-mesenteric sympathetic ganglia were fixed by a glutaraldehyde/formaldehyde-potassium dichromate-osmium treatment sequence and plastic-embedded. Fine sections were examined by electron probe x-ray microanalysis. Comparable peaks for chromium (Kalpha = 5.4 keV) were obtained from cytoplasmic fields containing membrane-bounded inclusion granules in both adrenomedullary noradrenaline cells and a type (type II) of sympathetic small granulated cell whose inclusion granules closely resemble those of the adrenomedullary noradrenaline cell. Chromium was not detected in granules within adrenomedullary adrenaline cells nor in two other sympathetic small granualted cell types. In no material was chromium detected in agranular cytoplasmic or nuclear fields. Since chromium binds to the Schiff monobase formed by glutaraldehyde and noradrenaline during fixation, we infer that noradrenaline is present in the granules of the type II sympathetic small granulated cell, as well as in adrenomedullary noradrenaline cells.

scholarly journals Combined Vital Dye Labelling and Catecholamine Histofluorescence of Transplanted Ciliary Ganglion Cells

1989 ◽  
Vol 1 (3-4) ◽  
pp. 113-128 ◽  
Author(s):  
John Sechrist ◽  
James N. Coulombe ◽  
Marianne Bronner-Fraser
Keyword(s):  
Neural Crest ◽  
Adrenal Medulla ◽  
Ganglion Cells ◽  
Large Cell ◽  
Cell Types ◽  
Sympathetic Ganglia ◽  
Variable Number ◽  
Ciliary Ganglion ◽  
Soma Size ◽  
Ganglion Neurons

We have utilized the carbocyanine dye, DiI, to label suspensions of dissociated ciliary ganglion cells removed from 6 to 12 day old quail embryos. Some of the cells were injected into the trunk somites of 2.5 - 3 day old chick embryos along pathways where neural crest cells migrate to form sensory and sympathetic ganglia, aortic plexuses and the adrenal medulla; the remainder of the cells were cultured to check their viability and the persistence of the DiI label. Embryos were incubated for 1 – 8 days post-injection, fixed in 4% paraformaldehyde/0.25% glutaraldehyde and processed for cryostat sectioning. DiI-labelled cells were readily identifiable in culture and in sections of embryos at all stages examined. Several cell types were identified, based on their morphology and soma size. These included cells with large cell bodies and bright DiI-labelling that appeared to be neurons and smaller, more weakly labelled cells that appeared non-neuronal. The latter presumably had divided several times, accounting for their reduced levels of dye. Many of the DiI-labelled cells were found in and around neural crest-derived sympathetic ganglia, aortic plexuses and adrenomedullary cords, but were rarely observed in dorsal root ganglia. The aldehyde fixative (Faglu mixture) used in this study reacts with catecholamines to form a bright reaction product in adrenergic cells including those in the sympathetic ganglia and the adrenal medulla. The catecholamine biproduct and the DiI in the same cell can easily be viewed with different fluorescent filter sets. A variable number of the DiI-labelled cells in these adrenergic sites contained catecholamines. Cells derived from younger 6 day ciliary ganglion dissociates exhibited detectable catecholamine neurotransmitters earlier and more frequently than those derived from 8 day embryos. The presence of cells exhibiting both bright DiI and catecholamine fluorescence is consistent with previous indications that post-mitotic ciliary ganglion neurons can undergo phenotypic conversion from cholinergic to adrenergic when transplanted to the trunk environment.

Improvements in the electron probe forming capabilities and x-ray hole counts in the Philips TEM

1983 ◽  
Vol 41 ◽  
pp. 376-377
Author(s):  
Richard L. McConville
Keyword(s):  
Field Strength ◽  
Electron Probe ◽  
Spherical Aberration ◽  
Focal Length ◽  
Objective Lens ◽  
Parallel Beam ◽  
Tilt Axis ◽  
X Ray ◽  
Small Probe ◽  
Specimen Height

A second generation twin lens has been developed. This symmetrical lens with a wider bore, yet superior values of chromatic and spherical aberration for a given focal length, retains both eucentric ± 60° tilt movement and 20°x ray detector take-off angle at 90° to the tilt axis. Adjust able tilt axis height, as well as specimen height, now ensures almost invariant objective lens strengths for both TEM (parallel beam conditions) and STEM or nano probe (focused small probe) modes.These modes are selected through use of an auxiliary lens situ ated above the objective. When this lens is on the specimen is illuminated with a parallel beam of electrons, and when it is off the specimen is illuminated with a focused probe of dimensions governed by the excitation of the condenser 1 lens. Thus TEM/STEM operation is controlled by a lens which is independent of the objective lens field strength.

Spatial resolution of X-ray microanalysis in thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 544-545
Author(s):  
R. Hutchings ◽  
I.P. Jones ◽  
M.H. Loretto ◽  
R.E. Smallman
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Beam Divergence ◽  
Inelastic Interaction ◽  
Specimen Thickness ◽  
High Current ◽  
Beam Spreading ◽  
X Ray ◽  
Thin Foils ◽  
Complex Calculation

There is increasing interest in X-ray microanalysis of thin specimens and the present paper attempts to define some of the factors which govern the spatial resolution of this type of microanalysis. One of these factors is the spreading of the electron probe as it is transmitted through the specimen. There will always be some beam-spreading with small electron probes, because of the inevitable beam divergence associated with small, high current probes; a lower limit to the spatial resolution is thus 2αst where 2αs is the beam divergence and t the specimen thickness.In addition there will of course be beam spreading caused by elastic and inelastic interaction between the electron beam and the specimen. The angle through which electrons are scattered by the various scattering processes can vary from zero to 180° and it is clearly a very complex calculation to determine the effective size of the beam as it propagates through the specimen.

High spatial resolution x-ray microanalysis of interfaces

1995 ◽  
Vol 53 ◽  
pp. 284-285
Author(s):  
J. R. Michael
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Solid Angle ◽  
Collection Efficiency ◽  
Spatial Scales ◽  
Energy Dispersive Spectrometer ◽  
X Rays ◽  
X Ray ◽  
Probe Size ◽  
Brightness Field

X-ray microanalysis in the analytical electron microscope (AEM) refers to a technique by which chemical composition can be determined on spatial scales of less than 10 nm. There are many factors that influence the quality of x-ray microanalysis. The minimum probe size with sufficient current for microanalysis that can be generated determines the ultimate spatial resolution of each individual microanalysis. However, it is also necessary to collect efficiently the x-rays generated. Modern high brightness field emission gun equipped AEMs can now generate probes that are less than 1 nm in diameter with high probe currents. Improving the x-ray collection solid angle of the solid state energy dispersive spectrometer (EDS) results in more efficient collection of x-ray generated by the interaction of the electron probe with the specimen, thus reducing the minimum detectability limit. The combination of decreased interaction volume due to smaller electron probe size and the increased collection efficiency due to larger solid angle of x-ray collection should enhance our ability to study interfacial segregation.

Microchemical imaging in biomedical research

1992 ◽  
Vol 50 (2) ◽  
pp. 1118-1119
Author(s):  
P. Ingram
Keyword(s):  
Data Analysis ◽  
Electron Probe ◽  
The Other ◽  
X Ray ◽  
Cell Element ◽  
Physiological Information ◽  
Functional States ◽  
Elemental Maps ◽  
Electron Energy Loss ◽  
Secondary Ion

It is well established that unique physiological information can be obtained by rapidly freezing cells in various functional states and analyzing the cell element content and distribution by electron probe x-ray microanalysis. (The other techniques of microanalysis that are amenable to imaging, such as electron energy loss spectroscopy, secondary ion mass spectroscopy, particle induced x-ray emission etc., are not addressed in this tutorial.) However, the usual processes of data acquisition are labor intensive and lengthy, requiring that x-ray counts be collected from individually selected regions of each cell in question and that data analysis be performed subsequent to data collection. A judicious combination of quantitative elemental maps and static raster probes adds not only an additional overall perception of what is occurring during a particular biological manipulation or event, but substantially increases data productivity. Recent advances in microcomputer instrumentation and software have made readily feasible the acquisition and processing of digital quantitative x-ray maps of one to several cells.

Reduction of Potassium in Kidney Proximal Tubules to Aid in Electron Probe X-Ray Microanalysis of Calcium

1985 ◽  
Vol 43 ◽  
pp. 474-475
Author(s):  
A. LeFurgey ◽  
P. Ingram ◽  
L.J. Mandel
Keyword(s):  
Smooth Muscle ◽  
Proximal Tubule ◽  
Electron Probe ◽  
Clinical Applications ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Target Cells ◽  
X Ray ◽  
Freeze Dried

For quantitative determination of subcellular Ca distribution by electron probe x-ray microanalysis, decreasing (and/or eliminating) the K content of the cell maximizes the ability to accurately separate the overlapping K Kß and Ca Kα peaks in the x-ray spectra. For example, rubidium has been effectively substituted for potassium in smooth muscle cells, thus giving an improvement in calcium measurements. Ouabain, a cardiac glycoside widely used in experimental and clinical applications, inhibits Na-K ATPase at the cell membrane and thus alters the cytoplasmic ion (Na,K) content of target cells. In epithelial cells primarily involved in active transport, such as the proximal tubule of the rabbit kidney, ouabain rapidly (t1/2= 2 mins) causes a decrease2 in intracellular K, but does not change intracellular total or free Ca for up to 30 mins. In the present study we have taken advantage of this effect of ouabain to determine the mitochondrial and cytoplasmic Ca content in freeze-dried cryosections of kidney proximal tubule by electron probe x-ray microanalysis.

scholarly journals In situ differentiation of iridophore crystallotypes underlies zebrafish stripe patterning

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dvir Gur ◽  
Emily J. Bain ◽  
Kory R. Johnson ◽  
Andy J. Aman ◽  
H. Amalia Pasoili ◽  
...  
Keyword(s):  
Skin Color ◽  
Cell Types ◽  
Color Pattern ◽  
Single Type ◽  
Sequencing Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cryogenic Scanning Electron Microscopy ◽  
Different Cell Types

AbstractSkin color patterns are ubiquitous in nature, impact social behavior, predator avoidance, and protection from ultraviolet irradiation. A leading model system for vertebrate skin patterning is the zebrafish; its alternating blue stripes and yellow interstripes depend on light-reflecting cells called iridophores. It was suggested that the zebrafish’s color pattern arises from a single type of iridophore migrating differentially to stripes and interstripes. However, here we find that iridophores do not migrate between stripes and interstripes but instead differentiate and proliferate in-place, based on their micro-environment. RNA-sequencing analysis further reveals that stripe and interstripe iridophores have different transcriptomic states, while cryogenic-scanning-electron-microscopy and micro-X-ray diffraction identify different crystal-arrays architectures, indicating that stripe and interstripe iridophores are different cell types. Based on these results, we present an alternative model of skin patterning in zebrafish in which distinct iridophore crystallotypes containing specialized, physiologically responsive, organelles arise in stripe and interstripe by in-situ differentiation.

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