Question

Nissl bodies found in neurons are-
A) Made of DNA
B) Masses of ribosome and RER
C) Help information on neurofibrils.
D) Masses of mitochondria.

Answer 1

Hint: Nissl bodies found in the cell body of the neurons are granules of rough endoplasmic reticulum (RER) with rosettes of free ribosomes.
The main function of Nissl bodies within neurons is to aid in the production and dispersal of chemical substances such as protein and peptides.

Complete Answer:
- A Nissl body is a large granular body found in neurons. These granules are of rough endoplasmic reticulum (RER) with rosettes of free ribosomes.
- And are the site of protein synthesis. Nissl bodies can be demonstrated by Nissl staining. Using an aniline stain to label extranuclear RNA granules. This staining method is useful to localize the cell body, as it can be seen in the soma and dendrites of neurons, though not in the axon or axon hillock. Due to RNA’s basophilic (“base-loving”) properties, it is stained blue by this method.
- Nissl bodies show changes under various physiological conditions and in pathological conditions, they may dissolve and disappear (chromatolysis). The ultrastructure of the Nissl body suggests they are primarily concerned with the synthesis of proteins for intracellular use.
- As Nissl bodies are made up of rough endoplasmic reticulum with plenty of ribosomes so their nature can be said as proteinaceous materials in pyramidal cells and nectar neurons, cells with long axons and distant terminals to maintain.

The correct answer is- (B) Masses of ribosome and RER.

Note: In living neurons, they are visible in phase contrast microscopy, the Nissl body represents the protein synthetic machinery of the cell. That shows Nissl substance is the granular or rough-surfaced endoplasmic reticulum (RER) found in other cells, especially those that synthesize protein in large amounts.