PNS, sensory ganglion (LM, High)

Structure List Spinal cord Dorsal root ganglion Dorsal root Neuron nuclei Satellite cell nuclei Axons Schwann cell nuclei Low Magnification View

When the cell bodies of neurons are located outside of the central nervous system, they are "glued" together in a structure called a ganglion. This slide shows the sensory ganglion (also called the spinal ganglion) which is located in the dorsal root of spinal nerves. These neurons are pseudo-unipolar. This means that the axon and the dendrite have fused, which facilitates rapid transmission of sensory information from the skin and other peripheral parts of the body to the dorsal or posterior horn of the gray matter of the spinal cord. Identify the large neurons which have many dense purple granules in their cytoplasm. This purple material is Nissl substance, or granular endoplasmic reticulum. The neurons have large nuclei with dense staining nucleoli. The cells immediately surrounding each neuron are the satellite, or supportive, cells for neurons in ganglia. Note that surrounding the neuron cell bodies are nerve fibers coming in bundles through the ganglion. The small nuclei out in these nerve bundles are from Schwann cells which surround each of the axons in these bundles.