9-36 Nervous tissue

GANGLION

A ganglion is a cluster of neuronal cell bodies located in the peripheral nervous system and surrounded by a thin layer of dense connective tissue.

The neurons of ganglia usually have large cell bodies with large nuclei containing loosely organized chromatin and prominent, often large nucleoli. Their cytoplasm frequently contains small basophilic granules, which correspond to groups of cisternae of the rough endoplasmic reticulum involved in protein synthesis. These structures are also known as Nissl bodies.

Each neuron cell body is surrounded by a layer of small, flattened cells called neuronal satellite cells or satellite glial cells. In the upper figure, the nuclei of these cells are highlighted in brown.

Lower figure: Neurons of a ganglion. The cytoplasm of the neuronal cell bodies is highlighted in pink, the nuclei in blue, the nucleoli in yellow, and the nuclei of satellite cells in green.