What is the purpose of Chromatolysis?
Chromatolysis is a reactive change that occurs in the cell body of damaged neurons, involving the dispersal and redistribution of Nissl substance (rough endoplasmic reticulum and polyribosomes) in order to meet an increased demand for protein synthesis such as is required to regenerate axons.
How does the Nissl stain work?
The Nissl substance (rough endoplasmic reticulum) appears dark blue due to the staining of ribosomal RNA, giving the cytoplasm a mottled appearance. Individual granules of extra-nuclear RNA are named Nissl granules (ribosomes). DNA present in the nucleus stains a similar color.
What is the Nissl substance?
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 is the function of Nissl granules in nerve cell?
Nissl’s granules are of the rough endoplasmic reticulum (RER) and contain free ribosomes. They are responsible for the synthesis of proteins which flow along the dendrites and the axon and replace the proteins which are broken down during cellular activity.
Why do we use Nissl stain?
Nissl-staining is a widely used method to study morphology and pathology of neural tissue. The described method facilitates the mapping of immunocytochemical signals and makes possible the light microscopic examination of the innervation of neurons identified by their nuclear protein content.
Is nissl granules absent in axon?
The Nissl’s granules are also present in dendrites of neurons. These are absent in axons and axon hillocks. So, the answer is, ‘Axon.
What is central Chromatolysis?
Central chromatolysis (arrow) occurs when the normal aggregations of rough endoplasmic reticulum and associated ribosomes, known as Nissl substance, in the neuronal perikaryon disperse as a response to injury. It signifies the acceleration of neuronal protein synthesis in the face of cellular injury.
What are Nissl’s granules give their functions?
Nissl’s Granules are the substances found in the neurons which are a large granular type of body. These granules are very useful for protein synthesis also help to transport these proteins to the part known as cyton.
What is the main function of nissl’s granules?
What is nissl granules consist of?
Nissl’s granules (or Nissl’s bodies) are the groups of ribosomes and rough endoplasmic reticulum. These are actively involved in the synthesis of proteins.