Lateral hypothalamus an OX1-induced CB1 pressor response in the rostral ventrolateral medulla. Narcolepsy is associated with a marked reduction in the number of orexinergic projection neurons from the lateral hypothalamus and very low orexin peptides in cerebrospinal fluid. This has been identified as the mechanism responsible for narcoleptic symptoms. Evidence suggest that OX1 neurons that synapse onto the dorsal nucleus of the vagus nerve and parts of the brain stem may play a role in the pathophysiology of chronic pain and visceral hypersensitivity in functional gastrointestinal disorders. Lateral hypothalamus The lateral hypothalamus, also called the lateral hypothalamic area, contains the primary orexinergic
Cerebellum via climbing fibers. Although the inferior olive lies in the medulla oblongata and receives input from the spinal cord, brainstem and cerebral cortex, its output goes entirely to the cerebellum. A climbing fiber gives off collaterals to the deep cerebellar nuclei before entering the cerebellar cortex, where it splits into about 10 terminal branches, each of which gives input to a single Purkinje cell. In striking contrast to the 100,000-plus inputs from parallel fibers, each Purkinje cell receives input from exactly one climbing fiber; but this single fiber "climbs" the dendrites of the Purkinje cell, winding around them and making