Short Nissl Staining for Incubated Cryostat Sections of the Brain

Nissl stain often binds poorly to cryostat sections which have been incubated in solutions of radiolabeled ligands. Such incubation is used in receptor autoradiography of the brain when using the in vitro method. We have developed a rapid (16 min) modification of Nissl staining for sections that bind stain poroly, e.g., incubated sections. The method stains well sections which cannot be stained with other rapid Nissl staining methods.     

Rapid Nissl Staining for Frozen Sections of Fresh Brain

Working with X-ray film autoradiography of soluble isotopes, we needed a staining technique for the localization of nuclei in frozen sections of fresh brain. We have found no Nissl staining method in the literature concerning autoradiography specially recommended for this purpose, nor have we found in handbooks on staining a Nissl method clearly recommended for unfixed, frozen sections of brain. The methods described are intended for paraffin or celloidin sections, and require fixation of brain before sectioning (which must be avoided when working with soluble isotopes). Because autoradiography is a time-consuming method, any technique which shortens time needed for the overall procedure is welcome. Most Nissl techniques described in the literature require long preprocessing of the tissue. We found two rapid methods, described by Humason (1967) and LaBossiere and Glickstein (1976), but their application to frozen sections did not give good results. After trials with several types of techniques, we succeeded in developing two Nissl modifications with slightly different qualities, one of 12 min and the other of 2-3 h. The longer method includes conventional steps in staining; the shorter method does not include fixation or lipid extraction. These methods were applied to 20-60 μm brain sections cut in the cryostat at -10 to -12 C and dried on gelatinized slides.     

A Tri-Basic-Dye Stain for Nerve Cells

A new staining method has been developed for the study of nerve cells and Nissl granules which combines three basic dyes, cresylecht violet, toluidine blue and thionin. The use of this tri-basic-dye stain results in finished preparations that are critically stained and permanent. Paraffin sections (4 μ sections preferably) are mounted on slides by the starch medium, deparaffinized and stained by the tribasic staining solution. After differentiation in acidified distilled water, sections are dehydrated, returned to stain solution and again dehydrated, then cleared and mounted in Clarite. Various vertebrate material including normal and pathological human tissues have been stained with this triple dye solution. Especially for pathological material, re-immersion of slides in the staining and 80% alcohol solutions before mounting, differentially intensifies the staining reaction. Fixatives used were 10% formalin, 95% alcohol, Bouin and formalin-Bouin (10% formalin followed by Bouin).     

Demonstration of lipofuscin and Nissl bodies in crystal violet stained sections using a fluorescence technique or pyronin Y stain

This paper presents two simple, reliable methods for identification of lipofuscin and Nissl bodies in the same section. One method shows that lipofuscin stained with crystal violet retains its ability to fluoresce and can be observed under the fluorescence microscope after the stain has faded. Fading is accompanied by a gradual increase in the intensity of the fluorescence and is complete in about 5 min. Exciting illumination from this part of the spectrum also substantially fades staining of other autofluorescing tissue elements, such as lipids. Nonfluorescing structures, such as Nissl bodies, remain stained. By changing from transillumination with tungsten light to epifluorescent illumination and vice versa, both types of structures--Nissl bodies and lipofuscin--can be identified in the same section. The second technique uses pyronin Y for staining Nissl bodies in preparations previously stained with crystal violet. Nissl bodies are stained pink but lipofuscin remains violet. Lipofuscin in these sections also remains autofluorescent after the crystal violet stain has faded under violet or near-UV light.     

Demonstration of Lipofuscin and Nissl Bodies in Crystal Violet Stained Sections Using a Fluorescence Technique or Pyronin Y Stain

This paper presents two simple, reliable methods for identification of lipofuscin and Nissl bodies in the same section. One method shows that lipofuscin stained with crystal violet retains its ability to fluoresce and can be observed under the fluorescence microscope after the stain has faded. Fading is accompanied by a gradual increase in the intensity of the fluorescence and is complete in about 5 min. Exciting illumination from this part of the spectrum also substantially fades staining of other autofluorescing tissue elements, such as lipids. Nonfluorescing structures, such as Nissl bodies, remain stained. By changing from transillumination with tungsten light to epifluorescent illumination and vice versa, both types of structures—Nissl bodies and lipofuscin—can be identified in the same section. The second technique uses pyronin Y for staining Nissl bodies in preparations previously stained with crystal violet. Nissl bodies are stained pink but lipofuscin remains violet. Lipofuscin in these sections also remains autofluorescent after the crystal violet stain has faded under violet or near-UV light.     

A combination staining method for fibers and cell bodies of the urodele central nervous system

A simple method for staining nerve cells and fibers of the salamander central nervous system is described. The procedure employs Carnoy's fixation followed by Protargol inpregnation and Nissl staining. This technique permits the simultaneous observation of intracellular neurofibrils, neuronal processes and basophilic components of the neuron. In addition, it eliminates the need to stain alternate sections with separate procedures to view the various components of the urodele central nervous system.     

A Combination Staining Method for Fibers and Cell Bodies of the Urodele Central Nervous System

A simple method for staining nerve cells and fibers of the salamander central nervous system is described. The procedure employs Carnoy's fixation followed by Protargol impregnation and Nissl staining. This technique permits the simultaneous observation of intracellular neurofibrils, neuronal processes and basophilic components of the neuron. In addition, it eliminates the need to stain alternate sections with separate procedures to view the various components of the urodele central nervous system.     

Silver Impregnation of Alzheimer's Neurofibrillary Changes Counterstained for Basophilic Material and Lipofuscin Pigment

A method is described in which selective silver staining of Alzheimer's neurofibrillary changes is combined with staining of cell nuclei, Nissl material, and lipofuscin granules. Formalin fixed, paraffin embedded sections of human autopsy tissue are silver stained according to a method proposed by Gallyas. Lipofuscin is stained by crotonaldehyde fuchsin following performic acid oxidation. Nissl substance is visualized by either Darrow red or gallocyanin-chrome alum staining. Architectonic units showing the specific pathology and the neuronal types prone to develop the neurofibrillary changes can be recognized using this technique.     

A differential stain for neuronal nucleoli in unfixed cryostat sections.

The Klüver-Barrera procedure, using luxol fast blue and cresyl violet for a combined nissl and myelin stain, was adapted to unfixed cryostat sections. Neuronal nucleoli appeared as distinct dark blue structures. The color contrast between violet Nissl substance and the nucleoli facilitated their recognition in human and in rat central nervous systems. This modified staining procedure enabled us to combine a counting of nerve cells with a histochemical investigation by applying each technique to a different set of sections cut from the same block of unfixed, frozen brain tissue.     

Silver impregnation of Alzheimer's neurofibrillary changes counterstained for basophilic material and lipofuscin pigment

A method is described in which selective silver staining of Alzheimer's neurofibrillary changes is combined with staining of cell nuclei, Nissl material, and lipofuscin granules. Formalin fixed, paraffin embedded sections of human autopsy tissue are silver stained according to a method proposed by Gallyas. Lipofuscin is stained by crotonaldehyde fuchsin following performic acid oxidation. Nissl substance is visualized by either Darrow red or gallocyanin-chrome alum staining. Architectonic units showing the specific pathology and the neuronal types prone to develop the neurofibrillary changes can be recognized using this technique.     

An Evaluation of Cresyl Echt Violet Acetate as a Nissl Stain

The new cresyl echt violet acetate, of which three different batches have been tested, proves to be a very useful Nissl stain. It is especially valuable for formalin-fixed, frozen-sectioned material. By using a buffered staining bath and controlled timing in dehydration it is possible, on paraffin embedded material, to use these dyes as progressive stains apparently specific for nucleic acids. With a saturated aqueous solution of the dye, especially when a mordant of lithium carbonate is used, it is possible to stain material that has been preserved in formalin for several years and also material from which nucleic acids have been removed. The dye is useful also for staining celloidin embedded material. With the buffered stain proposed, differentiation is much easier than with older methods which included a gross overstaining and a long destaining procedure.     

A Metachromatic Stain for Neural Tissue

The need for rapid histological feedback on neural tissue is ever present. Although there are several stains which can be readily used for staining either cell bodies or fiber tracts, adequate contrasting stains which are both rapid and easy to apply are not generally available. In 1936 Chang presented a technique for whole brains utilizing the metachromatic properties of thionin. Unfortunately this procedure was very time consuming. For the last several years we have worked with several variations of this stain and have found that thionin can be reliably used as a polychrome stain for sections of neural tissue obtained from a freezing microtome.     

Acid Thionin Stain for Nissl Bodies on Frozen Sections

Using a buffered acid thionin stain with carbolxylene as a clearing agent, a reliable stain for Nissl bodies may be performed on frozen sections of fresh or old formalin-fixed material in a relatively short period of time. The technic is simple: the buffering of thionin makes regressive differentiation unnecessary.     

A Teflon Disk for Processing Loose Serial Celloidin Sections

Celloidin sections are routinely used for Nissl, Golgi, or Golgi-Cox staining (e.g., Glaser and Van der Loos 1981) when sections thicker than 30 μm are required. In spite of the advantages of the celloidin method (see Voogd and Feirabend 1981, Buschke 1979), processing free-floating serial sections of celloidin embedded material, which may often be preferred, is not very convenient.     

A Combined Bodian-Nissl Stain for Improved Network Analysis in Neuronal Cell Culture

Bodian and Nissl procedures were combined to stain dissociated mouse spinal cord cells cultured on coverslips. The Bodian technique stains fine neuronal processes in great detail as well as an intracellular fibrillar network concentrated around the nucleus and in proximal neurites. The Nissl stain clearly delimits neuronal cytoplasm in somata and in large dendrites. A combination of these techniques allows the simultaneous depiction of neuronal perikarya and all afferent and efferent processes. Costaining with little background staining by either procedure suggests high specificity for neurons. This procedure could be exploited for routine network analysis of cultured neurons.     

A combined Bodian-Nissl stain for improved network analysis in neuronal cell culture

Bodian and Nissl procedures were combined to stain dissociated mouse spinal cord cells cultured on coverslips. The Bodian technique stains fine neuronal processes in great detail as well as an intracellular fibrillar network concentrated around the nucleus and in proximal neurites. The Nissl stain clearly delimits neuronal cytoplasm in somata and in large dendrites. A combination of these techniques allows the simultaneous depiction of neuronal perikarya and all afferent and efferent processes. Costaining with little background staining by either procedure suggests high specificity for neurons. This procedure could be exploited for routine network analysis of cultured neurons.     

Flat, Adherent, Well-Contrasted Semithin Plastic Sections for Light Microscopy

Semithin (0.5-2.0 μm) sections of plastic embedded specimens have long been used for identifying and orienting structures destined for electron microscopic observation. Improved staining methods and the development of more versatile plastics have increased the use of semithin plastic sections for histochemical and autoradiographic studies. The principal advantage of plastic over paraffin sections is the possibility of increased resolution. This advantage is often compromised, however, by problems arising during processing and staining. Wrinkles are common in sections containing tissues of different consistencies or when the hardness of the tissue does not match that of the surrounding plastic (Millonig 1980). Unfortunately, many of the methods designed to eliminate wrinkles (e.g., Alsop 1974, Sommer et al. 1979) require prolonged staining or repeated handling of the sections. Section adhesion problems usually arise during staining, particularly if the protocol requires alkaline or oxidizing reagents. Adhesives such as Mayer's albumen or chrome alum-gelatin (Hayat 1981) work well but may contribute to undesirable background staining or trapping of debris. A more complicated problem, inadequate stain contrast for photomicrography, usually can be traced to inability of the stain to penetrate the plastic, staining of the plastic, or nonspecific staining of the tissue. Alkaline staining solutions and chemicals which etch plastic can increase penetration, but may also cause section loss or staining of the plastic. The following is a simple method to eliminate these processing problems. It exploits the solvent properties and low surface tension of glycerol to aid in softening, flattening, and adhering semithin plastic sections to microscope slides.     

Optimization of a histopathological biomarker for sphingomyelin accumulation in acid sphingomyelinase deficiency

Niemann-Pick disease (types A and B), or acid sphingomyelinase deficiency, is an inherited deficiency of acid sphingomyelinase, resulting in intralysosomal accumulation of sphingomyelin in cells throughout the body, particularly within those of the reticuloendothelial system. These cellular changes result in hepatosplenomegaly and pulmonary infiltrates in humans. A knockout mouse model mimics many elements of human ASMD and is useful for studying disease histopathology. However, traditional formalin-fixation and paraffin embedding of ASMD tissues dissolves sphingomyelin, resulting in tissues with a foamy cell appearance, making quantitative analysis of the substrate difficult. To optimize substrate fixation and staining, a modified osmium tetroxide and potassium dichromate postfixation method was developed to preserve sphingomyelin in epon-araldite embedded tissue and pulmonary cytology specimens. After processing, semi-thin sections were incubated with tannic acid solution followed by staining with toluidine blue/borax. This modified method provides excellent preservation and staining contrast of sphingomyelin with other cell structures. The resulting high-resolution light microscopy sections permit digital quantification of sphingomyelin in light microscopic fields. A lysenin affinity stain for sphingomyelin was also developed for use on these semi-thin epon sections. Finally, ultrathin serial sections can be cut from these same tissue blocks and stained for ultrastructural examination by electron microscopy.     

Postembedding Staining of Brain Tissue for Ultrastructural Visualization of Amyloid in Alzheimer's Disease

A postembedding staining method is presented for ultrastructural visualization of amyloid deposits in brain sections from patients with Alzheimer's disease. Methenamine silver stain is applied to thin sections of tissue embedded in the acrylic resin LR Gold. Senile plaques are easily labeled by silver granules and the ultrastructural detail is well preserved. When staining time is prolonged, silver precipitate also is deposited on neuronal paired helical filaments. This method overcomes the drawbacks of previously reported applications of the stain on Vibra-tome and Epon sections. Thin sections from the same tissue block can be immunostained with antibodies to various plaque components, thus allowing comparative studies at the electron microscope level.     

Trypan blue in vivo stains nigral dopaminergic neurons killed by 6-hydroxydopamine

Dopaminergic neurons in the substantia nigra killed by 6-hydroxydopamine were stained in vivo by intracerebral injections of trypan blue. Such staining appeared specific for dead neurons, although a proportion of these retained the ability to stain with Nissl dyes for at least 2 days. Neurons retained trypan blue in vivo for periods of up to 9 days. Trypan blue staining of some neurons outside the substantia nigra demonstrated the use of this dye in determining the degree of non-specific toxicity of 6-hydroxydopamine. Twenty-four hours after infusion of trypan blue almost no background staining was present and individually stained neurons were clearly visible. Thus the use of trypan blue may have a general application as a sensitive method for estimating discrete areas of toxin-induced neuronal death, and for estimating the degree of specificity of a toxin.