Its subcortical structures include the hippocampus, basal ganglia and olfactory bulb. The nucleus accumbens core is part of the ventral striatum, located within the basal ganglia. There are also subcortical areas involved such as the basal ganglia and cerebellum. Axons from these leave the cortex and connect with subcortical structures including the basal ganglia. Na1.7 channels are expressed at high levels in nociceptive neurons of the dorsal root ganglia. The ciliary ganglion is one of four parasympathetic ganglia of the head. Neurons of the adjacent vestibular ganglia monitor the hair cells in these ducts. The limbic system also interacts with the basal ganglia. The striatum is the largest structure of the basal ganglia. The largest component of the basal ganglia is the striatum. The putamen is the outermost portion of the basal ganglia. Cranial nerve ganglia originated in the CNS. The ratio of the basal ganglia, diencephalon and brainstem combined is 11.35. There is a brain, a subesophageal ganglion, three thoracic ganglia, and six abdominal ganglia. Movement disorders are synonymous with basal ganglia or extrapyramidal diseases.