Dorsalganglion

Dorsal ganglion, commonly the dorsal root ganglion (DRG), is a cluster of sensory neuron cell bodies in the dorsal root of a spinal nerve. Each DRG sits along the dorsal root, usually in the intervertebral foramen adjacent to the spinal cord, and corresponds to a spinal segment.

The ganglion houses pseudounipolar neurons with peripheral and central processes; neuron cell bodies are surrounded by satellite glial cells and connective tissue. Unlike nuclei in the spinal cord, the DRG contains no synapses; transmission from periphery to CNS occurs via the central process entering the dorsal horn.

DRGs transduce somatic and visceral sensory information, including pain, temperature, touch, and proprioception. Their central processes form synapses within the dorsal horn and ascend to higher brain centers.

The DRG is a common site of pathology affecting sensory function. Nerve compression from disc herniation or foraminal stenosis can produce radicular pain. Reactivation of varicella-zoster virus in a DRG leads to shingles in a dermatomal distribution and may cause postherpetic neuralgia. Dorsal root ganglion stimulation is an approved neuromodulation strategy for certain chronic neuropathic pain conditions, targeting the DRG to modulate pain signaling.

DRGs originate from neural crest cells during embryonic development and show features of peripheral sensory neurons, including pseudounipolar morphology.