Nissl body

[2][3] The term "Nissl bodies" generally refers to discrete clumps of rough endoplasmic reticulum and free ribosomes in nerve cells.

Masses of rough endoplasmic reticulum also occur in some non-neuronal cells, where they are referred to as ergastoplasm, basophilic bodies,[1] or chromophilic substance.

[4] While these organelles differ in some ways from Nissl bodies in neurons,[5] large amounts of rough endoplasmic reticulum are generally linked to the copious production of proteins.

[1] "Nissl stains" refers to various basic dyes that selectively label negatively charged molecules such as DNA and RNA.

[6] They vary in size, shape, and intracellular location; they are most conspicuous in the motor neurons of the spinal cord and brainstem, where they appear as large, blocky assemblies.

Photomicrograph of Nissl bodies (two are indicated by arrows) in the cytoplasm of motor neurons in the anterior horn of the spinal cord ; cresyl violet stain (purple) along with a luxol fast blue stain for myelin . Scale bar = 30 microns (0.03mm).
Drawing of a motor neuron from the ventral horn of the medulla spinals of a rabbit. The angular and spindle-shaped Nissl bodies in the cytoplasm are well shown.