Fastigial nucleus

The fastigial nucleus is located in the cerebellum. It is one of the four deep cerebellar nuclei (the others being the nucleus dentatus, nucleus emboliformis and nucleus globosus), and is grey matter embedded in the white matter of the cerebellum.
It refers specifically to the concentration of gray matter nearest to the middle line at the anterior end of the superior vermis, and immediately over the roof of the fourth ventricle, from which it is separated by a thin layer of white matter. It is smaller than the nucleus dentatus, but somewhat larger than the nucleus emboliformis and nucleus globosus. The fastigial nucleus is the smallest in size, with the dentate being the largest and the interposed being intermediate in size.