According to NCERT nissl granule are present in dendrites and cyton of neuron which help in increases metabolic activities.
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Nissl granules, also known as Nissl bodies or Nissl substance, are specialized structures found within the cytoplasm of neurons. They were first described by German psychiatrist and neuropathologist Franz Nissl in the late 19th century. Nissl granules play a crucial role in the functioning and metabolism of neurons.

Function of Nissl Granules:
Nissl granules have several important functions within neurons, including:
1. Protein synthesis: Nissl granules are involved in the production of proteins necessary for the growth, maintenance, and functioning of neurons. They contain ribosomes, which are responsible for protein synthesis.
2. Nutrient storage: These granules store various nutrients required by the neuron, such as glucose and amino acids. These nutrients are essential for energy production and maintaining the overall metabolic activity of the neuron.
3. Metabolic support: Nissl granules provide metabolic support to neurons by producing and supplying proteins necessary for the cell's functions. These proteins are involved in various cellular processes, including signal transduction, ion channel regulation, and neurotransmitter synthesis.
4. Neuronal plasticity: Nissl granules contribute to neuronal plasticity, which is the ability of neurons to adapt and change their structure and function in response to stimuli or learning. They play a role in the growth and remodeling of neuronal processes, such as dendrites and axons.
5. Protection against stress: Nissl granules can also provide protection against cellular stress. During periods of stress or injury, they may form stress granules, which help to regulate and protect the cell's genetic material and prevent the accumulation of harmful proteins.
6. Identification of neuronal types: The presence and distribution of Nissl granules can be used to identify different types of neurons. The staining patterns of Nissl granules in neuronal cell bodies are often used in histological studies to distinguish between different types of neurons and to study the organization of neuronal circuits.

In summary, Nissl granules are specialized structures found in the cytoplasm of neurons. They play a crucial role in protein synthesis, nutrient storage, metabolic support, neuronal plasticity, protection against stress, and identification of neuronal types. These granules are essential for the proper functioning and maintenance of neurons, and any abnormalities in Nissl granules can have significant implications for neuronal health and function.