Red nucleus

The red nucleus (from Latin nucleus " core " and ruber "red", " red core " ) is a collection of nerve cells (core) of the midbrain. On a cross-section it is macroscopically seen in humans as large, round, reddish colored core. The color is produced by the high iron content in the cell bodies.

Histology

The red nucleus is divided into two sections. The pars magnocellularis consists of large cells and is evolutionarily older part. Pars parvocellularis consists of small cells and forms the larger part of the core.

Function

The red nucleus is a key connection in the motor system. He projected his efferents to the spinal cord, thereby providing an important part of the extrapyramidal system. He takes over circuits with the Nucleus emboliform of the cerebellum to influence muscle tone and posture.

The red nucleus is part of a neural loop ( Guillain- Mollaret Triangle ), which forms a kind of feedback mechanism: it receives as part of the extrapyramidal system information from the motor cortex and passes them on to executive motor centers in the spinal cord. At the same time it sends information about what he has received and forwarded by the cerebrum, on the Olive to the dentate nucleus of the cerebellum. This in turn has his hand on the nucleus ruber one. At each of these stages a match and modulation of the incoming information takes place.

The significance of these neurons loop is in a constant balancing of the centrally generated motor impulses with their peripheral execution. This is for the high precision with which people ( and higher vertebrates in general) can move their body parts and control their posture is crucial.

Afferents

The red nucleus receives input from:

  • Cerebellum via the Fibrae cerebellorubrales
  • Superior colliculus
  • Precentral gyrus on the Fibrae corticorubrales
  • Pallidum
  • Thalamus
  • Vestibular nuclei

Efferents

The red nucleus sends signals:

  • Olivary nucleus via the optic tract rubroolivaris
  • Spinal cord via the optic tract rubrospinalis
  • Reticular formation via the optic tract rubroreticularis
  • Tract rubrotectalis
  • Thalamus via the tracts rubrothalamicus

Damage

A lesion of the red nucleus in humans caused on the contralateral side an intention tremor and a decrease in muscle tone. Furthermore choreic - athetoid movements can occur. In non-primate usually occur contralateral paralysis ( hemiparesis ), possibly with gait disorders and disturbed posture and position reactions.

  • Heartland
  • Mesencephalon
Nucleus (neuroanatomy) Motor neuron Emboliform nucleus Myoclonic triangle Huntington's disease
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