Nucleus ruber

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Position of the ruber nucleus (8), frontal section

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

histology

The ruber nucleus is divided into two sections. The pars magnocellularis consists of large cells and historically forms the older part. The pars parvocellularis consists of small cells and forms the larger part of the nucleus.

function

The ruber nucleus is an important control point in the motor system . With its efferents, it projects into the spinal cord and thus provides an important part of the extrapyramidal motor system . It influences muscle tone and posture via circuits with the nucleus emboliformis of the cerebellum .

The ruber nucleus is part of a neuron loop ( Guillain-Mollaret triangle ) that forms a kind of feedback mechanism: As part of the extrapyramidal motor system, it receives information from the motor cerebral cortex and forwards it to the executive motor centers in the spinal cord. At the same time, it sends information about what it has received and transmitted from the cerebrum via the olive to the dentate nucleus of the cerebellum . This in turn acts on the nucleus ruber. At each of these levels there is an adjustment and modulation of the incoming information.

The importance of this neuron loop is a constant comparison of the centrally generated motor impulses with their peripheral execution. This is vital to the tremendous precision with which humans (and higher vertebrates in general) can move their body parts and control their posture.

Afferents

The nucleus ruber receives impulses from:

Efferents

The nucleus ruber sends signals to:

Injuries

Damage to the ruber nucleus in humans causes an intention tremor on the opposite ( contralateral ) side and a reduction in muscle tone . In addition, choreic-athetotic movements can occur. In non-primates, contralateral paralysis ( hemiparesis ), possibly with gait disturbances and disturbed posture and posture reactions , usually occur (see also: contralaterality of the forebrain ).

This text is based in whole or in part on the entry Nucleus ruber in Flexikon , a wiki from DocCheck . The takeover took place on July 21, 2004 under the then valid GNU license for free documentation .