The neuronal cell body consists of a large nucleus with a ruffled nuclear membrane, sparse chromatin, and a conspicuous nucleolus, in which the cytoplasm is composed of Nysted 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. Nissen granules can be visualized with a number of stains such as neutral red, methylene blue, toluidine blue, and methyl violet, and the variability of staining, pH, and time of differentiation allows some stains to highlight both the Nissen material alone and the nucleus and glia of the neuron. Nissl bodies, or Nissl vesicles, are small triangular or oval shaped masses distributed in the cytoplasm of nerve cells that can be stained violet-blue by basic dyes such as sulfur cordyceps, methylene blue, toluidine blue, and tar violet, etc. Nissl bodies are found in all types of nerve cells, but their shapes, numbers, and distribution are often different, and they are found in dendrites as well, but not axons and axonemes of the periphery. ; Nichols' bodies change as a result of changes in physiological status, Nichols' bodies are an important site for synthesizing protein synthesis within neurons, and when a neuron is stimulated, the number of Nichols' bodies within the envelope decreases markedly.

Nissl Stain (Nissl Stain, tar violet method) adopts tar violet (Cresyl violet) as the core dye, tar violet has a light-sensitive effect, which can well show the changes of Nissl bodies, the main advantages are easy operation, stable staining, wide range of application, and can be used for staining of the Nissl substances, neurons and so on in the paraffin tissue sections, the presence and disappearance of Nissl bodies is an The presence and disappearance of nidus is an important indicator of whether the nerve cells are damaged or not. When encephalitis, cerebral ischemia, axonal reaction, etc. occur, the nidus will dissolve or even disappear.