Deep cerebellar nuclei

The cerebellum has four deep cerebellar nuclei embedded in the white matter in its center.Cross-section of human cerebellum, showing the dentate nucleus, as well as fourth ventricleCross-section of human cerebellum, showing the dentate nucleus and cross-section of vermis The cerebellum has four deep cerebellar nuclei embedded in the white matter in its center. These nuclei receive inhibitory (GABAergic) inputs from Purkinje cells in the cerebellar cortex and excitatory (glutamatergic) inputs from mossy fiber and climbing fiber pathways. Most output fibers of the cerebellum originate from these nuclei. One exception is that fibers from the flocculonodular lobe synapse directly on vestibular nuclei without first passing through the deep cerebellar nuclei. The vestibular nuclei in the brainstem are analogous structures to the deep nuclei, since they receive both mossy fiber and Purkinje cell inputs. From lateral to medial, the four deep cerebellar nuclei are the dentate, emboliform, globose, and fastigii. Some animals, including humans, do not have distinct emboliform and globose nuclei, instead having a single, fused interposed nucleus. In animals with distinct emboliform and globose nuclei, the term interposed nucleus is often used to refer collectively to these two nuclei.