The fastigial nucleus
or nucleus fastigii
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 other two independent centers of gray matter in the cerebellum
Relations and function
The fastigial nucleus receives its afferent input from the flocculonodular lobe
and the vermis
. Most of its efferent connections travel via the inferior cerebellar peduncle
to the vestibular nuclei
, which is located at the junction of the pons
The fastigial nucleus deals with antigravity muscle groups and other synergies involved with standing and walking.
The fastigial nucleus contains excitatory axons which project beyond the cerebellum, unlike the Purkinje cells that convey the purely-inhibitory output of the cerebellar cortex. The likely neurotransmitters of the excitatory fastigial nucleus axons are glutamate and aspartate.
The Purkinje cells of the cerbellar cortex project into the deep cerebellar nuclei and inhibit the excitatory output system.