Contents
What are the nissl bodies?
Nissl bodies (also called Nissl granules Nissl substance or tigroid substance) are discrete granular structures in neurons that consist of rough endoplasmic reticulum, a collection of parallel, membrane-bound cisternae studded with ribosomes on the cystosolic surface of the membranes.
What color are nissl bodies?
blue purple
Nuclei and nissl bodies (rough endoplasmic reticulum) are stained blue purple with cresyl violet.
Are nissl bodies nucleoli?
The Nissl stain is most intense in nucleoli and in the rough endoplasmic reticulum of neurons. For myelinated axons in the nervous system, a variety of techniques selectively label the unique physical properties of the densely wound membranes.
Is generally short with many branches and contains Nissl?
bodies called Nissl’s granules. Short fibres which branch repeatedly and project out of the cell body also contain Nissl’s granules and are called dendrites. These fibres transmit impulses towards the cell body. The axon is a long fibre, the distal end of which is branched.
What creates the myelin sheath?
Schwann cells make myelin in the peripheral nervous system (PNS: nerves) and oligodendrocytes in the central nervous system (CNS: brain and spinal cord). In the PNS, one Schwann cell forms a single myelin sheath (Figure 1A).
Why do neuronal bodies stain blue?
Because ammonium sulfide is a reducing agent, the stain is initially decolorized and the cell bodies appear blue only during fixation and dehydration. This makes differentiation somewhat difficult to control, and after dehydration it may be necessary to return to fixative for further differentiation.
What causes Chromatolysis?
Chromatolysis is the dissolution of the Nissl bodies in the cell body of a neuron. It is an induced response of the cell usually triggered by axotomy, ischemia, toxicity to the cell, cell exhaustion, virus infections, and hibernation in lower vertebrates.
What is nissl?
Nissl substance is a reticulum of channels within neurons. Its external membranes are studded with rows, loops, and spirals of ribosomes, although some regions are smooth. Ribosomes also lie free in the cytoplasm as polysomal rosettes between cisternae.
What kind of structure is a Nissl body?
Nissl bodies are considered to be cumulative rough endoplasmic reticulum . In other words, they are structures formed by parallel cisterns with ribosomes (enzymatic structures made of ribosomal RNA) adhered in a spiral, in which, in addition, free polyribosomes can also be seen.
Where are the Nissl bodies found in neurons?
The Nissl bodies , Also called substance of Nissl, is a structure that is in the interior of the neurons. In particular, it is observed in the nucleus of the cell (called soma) and in the dendrites. The axons or nerve extensions through which neural signals travel never lack Nissl bodies.
What kind of dye is used to identify Nissl bodies?
In addition to methylene blue, many other dyes are used to look at the sums of cells. The most used is cresyl violet. This has allowed to identify masses of cellular sums, besides the location of the bodies of Nissl. The bodies of Nissl are accumulations of Rough endoplasmic reticulum (RER).
What does a Nissl stain look like on the nucleus?
With a cresyl violet Nissl stain, the nucleic acid appears dark purple-blue while the areas with low nucleic acid density appears light blue-gray. The center of the nucleus is the nucleolus, the actual site of storage for DNA.