Name: Vídeo: Coloração de prata para visualizar placas neuríticas em uma seção cerebral com doença de Alzheimer - Experimento
Uploaded: 2025-03-04T15:34:54.000+00:00
Duration: 1 min 21 s
Description: 36 visualizações. Coloração de prata para visualizar placas neuríticas em uma seção cerebral com doença de Alzheimer

silver staining to visualize neuritic plaques in an alzheimer&#39;s diseased brain section

Silver Staining to Visualize Neuritic Plaques in an Alzheimer&#39;s Diseased Brain Section

Neuritic plaques (NPs) are extracellular amyloid-&#946; aggregates surrounded by damaged nerve endings, characteristic of Alzheimer&#39;s disease pathology.
To visualize these NPs, take a deparaffinized, fixed human brain section.
Treat the section with periodic acid to oxidize reactive groups in NPs, enhancing their reactivity.
Wash with distilled water to remove residual acid.
Incubate the section in alkaline silver iodide, allowing silver ions to bind to the oxidized reactive groups.
Wash with a mild acid and rinse in distilled water.
Add a developer solution containing a reducing agent to reduce silver ions into metallic silver, forming a brown stain on the NPs.
Wash with mild acid and distilled water.
Apply gold chloride to enhance stain contrast. Rinse with distilled water.
Treat with sodium thiosulfate to stabilize the stain and rinse again.
Dehydrate the section and mount it.
Using a light microscope, visualize the darkly stained NPs within the section.

silver-staining-to-visualize-neuritic-plaques-an-alzheimer-s-diseased

Nanyang Technological University

Research

JoVE Encyclopedia of Experiments

Neuroscience

Neuropathology

Neurodegenerative Diseases

36 visualizações. Coloração de prata para visualizar placas neuríticas em uma seção cerebral com doença de Alzheimer

Vídeo: Coloração de prata para visualizar placas neuríticas em uma seção cerebral com doença de Alzheimer - Experimento

Labeling and Imaging of Amyloid Plaques in Brain Tissue Using the Natural Polyphenol Curcumin

Deposition of amyloid beta protein (A&#946;) in extra- and intracellular spaces is one of the hallmark pathologies of Alzheimer&#39;s disease (AD). Therefore, detection of the presence of A&#946; in AD brain tissue is a valuable tool for developing new treatments to prevent the progression of AD. Several classical amyloid binding dyes, fluorochrome, imaging probes, and A&#946;-specific antibodies have been used to detect A&#946; histochemically in AD brain tissue. Use of these compounds for A&#946; detection is costly and time consuming. However, because of its intense fluorescent activity, high-affinity, and specificity for A&#946;, as well as structural similarities with traditional amyloid binding dyes, curcumin (Cur) is a promising candidate for labeling and imaging of A&#946; plaques in postmortem brain tissue. It is a natural polyphenol from the herb Curcuma longa. In the present study, Cur was used to histochemically label A&#946; plaques from both a genetic mouse model of 5x familial Alzheimer&#39;s disease (5xFAD) and from human AD tissue within a minute. The labeling capability of Cur was compared to conventional amyloid binding dyes, such as thioflavin-S (Thio-S), Congo red (CR), and Fluoro-jade C (FJC), as well as A&#946;-specific antibodies (6E10 and A11). We observed that Cur is the most inexpensive and quickest way to label and image A&#946; plaques when compared to these conventional dyes and is comparable to A&#946;-specific antibodies. In addition, Cur binds with most A&#946; species, such as oligomers and fibrils. Therefore, Cur could be used as the most cost-effective, simple, and quick fluorochrome detection agent for A&#946; plaques.

Curcumin is an ideal fluorophore for labeling and imaging of amyloid beta protein plaques in brain tissue due to its preferential binding to amyloid beta protein as well as its structural similarities with other traditional amyloid binding dyes. It can be used to label and image amyloid beta protein plaques more efficiently and inexpensively than traditional methods.

Rotulagem e imagem de placas amilóides no tecido cerebral usando a curcumina polifenóis naturais

Deposition of amyloid beta protein (A&#946;) in extra- and intracellular spaces is one of the hallmark pathologies of Alzheimer&#39;s disease (AD). ...

JoVE Journal

Neurociência

Full- versus Sub-Regional Quantification of Amyloid-Beta Load on Mouse Brain Sections

Extracellular accumulation of amyloid-beta (A&#946;) plaques is one of the major pathological hallmarks of Alzheimer's disease (AD), and is the target of the only FDA-approved disease-modifying treatment for AD. Accordingly, the use of transgenic mouse models that overexpress the amyloid precursor protein and thereby accumulate cerebral A&#946; plaques are widely used to model human AD in mice. Therefore, immunoassays, including enzyme-linked immunosorbent assay (ELISA) and immunostaining, commonly measure the A&#946; load in brain tissues derived from AD transgenic mice. Though the methods for A&#946; detection and quantification have been well established and documented, the impact of the size of the region of interest selected in the brain tissue on A&#946; load measurements following immunostaining has not been reported. Therefore, the current protocol aimed to compare the A&#946; load measurements across the full- and sub-regions of interest using an image analysis software. The steps involved in brain tissue preparation, free-floating brain section immunostaining, imaging, and quantification of A&#946; load in full- versus sub-regions of interest are described using brain sections derived from 13-month-old APP/PS1 double transgenic male mice. The current protocol and the results provide valuable information about the impact of the size of the region of interest on A&#946;-positive area quantification, and show a strong correlation between the A&#946;-positive area obtained using the full- and sub-regions of interest analyses for brain sections derived from 13-month-old male APP/PS1 mice that show widespread A&#946; deposition.

The present protocol describes and compares the procedure to perform a full-region or sub-region of interest analysis of sagittal mouse brain sections to quantify amyloid-beta load in the APP/PS1 transgenic mouse model of Alzheimer's disease.

Quantificação total versus sub-regional da carga amilóide-beta nas seções cerebrais do rato

Extracellular accumulation of amyloid-beta (A&#946;) plaques is one of the major pathological hallmarks of Alzheimer's disease (AD), and is the target of ...

Detection of Glycosaminoglycans by Polyacrylamide Gel Electrophoresis and Silver Staining

Sulfated glycosaminoglycans (GAGs) such as heparan sulfate (HS) and chondroitin sulfate (CS) are ubiquitous in living organisms and play a critical role in a variety of basic biological structures and processes. As polymers, GAGs exist as a polydisperse mixture containing polysaccharide chains that can range from 4000 Da to well over 40,000 Da. Within these chains exists domains of sulfation, conferring a pattern of negative charge that facilitates interaction with positively charged residues of cognate protein ligands. Sulfated domains of GAGs must be of sufficient length to allow for these electrostatic interactions. To understand the function of GAGs in biological tissues, the investigator must be able to isolate, purify, and measure the size of GAGs. This report describes a practical and versatile polyacrylamide gel electrophoresis-based technique that can be leveraged to resolve relatively small differences in size between GAGs isolated from a variety of biological tissue types.

This report describes techniques to isolate and purify sulfated glycosaminoglycans (GAGs) from biological samples and a polyacrylamide gel electrophoresis approach to approximate their size. GAGs contribute to tissue structure and influence signaling processes via electrostatic interaction with proteins. GAG polymer length contributes to their binding affinity for cognate ligands.

Detecção de glicosaminoglicanos por Electrophoresis gel poliacrilamida e coloração de prata

Sulfated glycosaminoglycans (GAGs) such as heparan sulfate (HS) and chondroitin sulfate (CS) are ubiquitous in living organisms and play a critical role ...

Silver Staining to Visualize Neuritic Plaques in an Alzheimer's Diseased Brain Section

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