(singular: ganglion) Colonies of neurons outside the brain and spinal cord sometimes acting to control local functions. These are little affected by normal stress conditions. (Example: the solar plexus, made of two separate ganglions.)
Paired nerve cell clusters deep within the cerebrum (the main mass of the brain) and upper part of the brainstem.
The basal ganglia play a vital part in producing smooth, continuous muscular actions and in stopping and starting movement.
Any disease or degeneration affecting the basal ganglia and their connections may lead to the appearance of involuntary movements, trembling, and weakness, as occur in Parkinson’s disease.... basal ganglia
These are swellings on the dorsal roots of spinal nerves just proximal to the union of the dorsal and ventral nerve roots. They are situated in the inter-vertebral foramina and contain the cell bodies of sensory neurones. (See SPINAL COLUMN; SPINAL CORD.)... dorsal root ganglia
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