The

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...

has four deep cerebellar nuclei embedded in the white matter in its center. 4 pairs of nuclei are embedded deep in the medullary centre, in the medial to lateral direction. They are fastigial nuclei, globose nuclei, emboliform nuclei, dentate nuclei.

Inputs

These nuclei receive

inhibitory An inhibitory postsynaptic potential (IPSP) is a kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.Purves et al. Neuroscience. 4th ed. Sunderland (MA): Sinauer Associates, Incorporated; 2008. ...

( GABAergic) inputs from

Purkinje cells Purkinje cells, or Purkinje neurons, are a class of GABAergic inhibitory neurons located in the cerebellum. They are named after their discoverer, Czech anatomist Jan Evangelista Purkyně, who characterized the cells in 1839. Structure T ...

in the cerebellar cortex and

excitatory In neuroscience, an excitatory postsynaptic potential (EPSP) is a postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential. This temporary depolarization of postsynaptic membrane potential, caused by the ...

(

glutamate Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...

rgic) inputs from mossy fiber and

climbing fiber Climbing fibers are the name given to a series of neuronal projections from the inferior olivary nucleus located in the medulla oblongata. These axons pass through the pons and enter the cerebellum via the inferior cerebellar peduncle whe ...

pathways. Most output fibers of the cerebellum originate from these nuclei. One exception is that fibers from the

flocculonodular lobe The flocculonodular lobe (vestibulocerebellum) is a lobe of the cerebellum consisting of the nodule and the flocculus. The two flocculi are connected to the midline structure called the nodulus by thin pedicles. It is placed on the anteroinferio ...

synapse directly on

vestibular nuclei The vestibular nuclei (VN) are the cranial nuclei for the vestibular nerve located in the brainstem. In Terminologia Anatomica they are grouped in both the pons and the medulla in the brainstem. Structure Path The fibers of the vestibular n ...

without first passing through the deep cerebellar nuclei. The vestibular nuclei in the

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is cont ...

are analogous structures to the deep nuclei, since they receive both mossy fiber and Purkinje cell inputs.

Specific nuclei

From lateral to medial, the four deep cerebellar nuclei are the

dentate Dentate may refer to: * A species having dentition * An energy-dissipating baffle block in a spillway * An individual not being edentulous * Dentate gyrus of the hippocampus * Dentate nucleus of the cerebellum * Denticity in chemistry * Dentat ...

, emboliform,

globose A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the ...

, and fastigii. Some animals, including humans, do not have distinct emboliform and globose nuclei, instead having a single, fused

interposed nucleus The interposed nucleus is part of the deep cerebellar complex and is composed of the globose nucleus and the emboliform nucleus. It is located in the roof (dorsal aspect) of the fourth ventricle, lateral to the fastigial nucleus. It receives its ...

. In animals with distinct emboliform and globose nuclei, the term ''interposed nucleus'' is often used to refer collectively to these two nuclei.

Topography

In general, each pair of deep nuclei is associated with a corresponding region of cerebellar surface anatomy. File:Sobo 1909 657.png, Cross-section of human cerebellum, showing the dentate nucleus, as well as fourth ventricle File:Sobo 1909 658.png, Cross-section of human cerebellum, showing the dentate nucleus and cross-section of vermis * The dentate nuclei are deep within the lateral hemispheres, * the interposed nuclei are located in the paravermal (intermediate) zone, * and the fastigial nuclei are in the

vermis The cerebellar vermis (from Latin ''vermis,'' "worm") is located in the medial, cortico-nuclear zone of the cerebellum, which is in the posterior fossa of the cranium. The primary fissure in the vermis curves ventrolaterally to the superior s ...

. These structural relationships are generally maintained in the neuronal connections between the nuclei and associated cerebellar cortex, * with the dentate nucleus receiving most of its connections from the lateral hemispheres, * the interposed nuclei receiving inputs mostly from the paravermis, * and the fastigial nucleus receiving primarily afferents from the vermis.

References

External links

* * https://web.archive.org/web/20150621011739/http://www.mona.uwi.edu/fpas/courses/physiology/neurophysiology/Cerebellum.htm {{Authority control Cerebellum