Neural Control and Coordination Question 26
26. The Nissl’s granules of nerve cells are made up of
[1997, 03]
(a) ribosomes
(b) proteins
(c) DNA
(d) mitochondria
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Answer : a
Hints & Solutions
(a) Prominent granules (Nissl’s granules) observed in the cytoplasm of the cyton are believed to be made of ribosomes. A Nissl body (or Nissl granule or tigroid body) is a large granular body found in nerve cells. It was named after Franz Nissl, German neurologist (1860-1919). Nissl bodies can be demonstrated by selective staining, which was developed by Nissl and the stain used was an aniline stain to label extranuclear RNA granules. These granules are rough endoplasmic reticulum (with ribosomes) and are the site of protein synthesis. Nissl bodies show changes under various physiological conditions and in pathological conditions they may dissolve and disappear (karyolysis).
