The neuronal cell body consists of a large nucleus with a ruffled nuclear membrane, sparse chromatin, and a distinct nucleolus, in which the cytoplasm is composed of Nysted's granules, i.e., basophilic granules that are representative of the rough endoplasmic reticulum and that give rise to specific patchy basophilic manifestations in many neurons. Nysted granules can be visualized with many stains such as neutral red, methylene blue, toluidine blue and methyl violet. Variations in staining, pH, and time of differentiation allow some stains to highlight both the Nissl substance alone and the nucleus and glia of the neuron; Nissl bodies, or Nissl microsomes, are small, triangular or oval shaped masses distributed in the cytoplasm of neuronal cells that can be stained a purplish-blue color by alkaline dyes such as sulfur cordyceps, methylene blue, toluidine blue, and tar violet; all kinds of neuronal cells All kinds of nerve cells contain niosomes, but their shapes, numbers, and distribution locations are often different. Niosomes are also found in dendrites, but not in axons and axon thalamus of the periphery; Niosomes change due to physiological changes, and niosomes are an important site for synthesizing proteins within the neuron, and niosomes within the periphery are significantly reduced when the neuron is stimulated.

The main advantages of Nissl Stain (Nissl Stain, methylene blue method) are easy operation, stable staining, and wide range of application, which can be used for staining of nissl substances, neurons, etc. in paraffin tissue sections; the presence and disappearance of nissl bodies is an important indicator of whether the nerve cells are damaged or not, and when encephalitis, cerebral ischemia, and axon reaction occur, the nissl bodies will undergo dissolution or even disappear.