Red nucleus

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)

Brain: Red nucleus

Transverse section through the midbrain showing the location of the red nuclei. The superior colliculi are at the top of image and the cerebral peduncles at the bottom of image – both in section.
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Latin	nucleus ruber
Gray's	subject #188 802
Part of
Components
Artery
Vein
BrainInfo/UW	hier-496
MeSH	A08.186.211.132.659.822.642

Main article: mesencephalon

The red nucleus is a structure in the rostral midbrain involved in motor coordination. It comprises a caudal magnocellular and a rostral parvocellular part.

Function[]

In animals without a significant corticospinal tract, gait is mainly controlled by the red nucleus.

In humans, the red nucleus mainly controls the muscles of the shoulder and upper arm, but it has some control over the lower arm and hand as well. It is less important in its motor functions for humans than in many other mammals, because, in humans, the corticospinal tract is dominant. However the crawling of babies is controlled by the red nucleus, as is arm-swinging in normal walking. Since the red nucleus has sparse control over hands (as the Rubrospinal tract is more involved in large muscle movement such as that for Arms and Legs), fine control of the fingers is not modified by the functioning of the red nucleus (rather it relies on the corticospinal tract).

Input and output[]

The red nucleus receives many inputs from the contralateral cerebellum (interpositus nucleus and lateral cerebellar nucleus) and an input from the ipsilateral motor cortex.

It sends efferent axons (the rubrospinal projection) to the contralateral half of the rhombencephalic reticular formation and spinal cord. These efferent axons cross just ventral to the nucleus and descend through the midbrain to the spinal cord, where the rubrospinal tract which they make up runs ventral to the lateral corticospinal tract in the lateral funiculus. Second bundle of fibers continues ipsilaterally through the medial tegmental field towards inferior olive.