Centromedian nucleus

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In the anatomy of the brain, the centromedian nucleus, also known as the centrum medianum, (CM or Cm-Pf) is a part of the intralaminar nucleus (ILN) of the thalamus. There are two centromedian nuclei arranged bilaterally.

It contains about 2000 neurons per cubic millimetre and has a volume of about 300 cubic millimetres with 600,000 neurons in total.

Input and output

It sends nerve fibres to the caudate, putamen and collateral fibres to the cerebral cortex. It receives nerve fibres from the cerebral cortex, vestibular nuclei, globus pallidus, superior colliculus, reticular formation, and spinothalamic tract.

Function

Its physiological role involves attention and arousal, including control of the level of cortical activity. Some frequencies of extracellular electrical stimulation of the centromedian nucleus can cause absence seizures (temporary loss of consciousness) although electrical stimulation can be of therapeutic use in intractable epilepsy and Tourette's syndrome. General anaesthetics specifically suppress activity in the ILN, including the centromedian nucleus. Complete bilateral lesions of the centromedian nucleus can lead to states normally associated with brain death such as coma, death, persistent vegetative state, forms of mutism and severe delirium. Unilateral lesions can lead to unilateral thalamic neglect.

Some have suggested the controversial notion that human consciousness resides fully or at least mainly in the centromedian nucleus.

Additional images

External links

• - The Global Thalamus (See level 12, the centromedian nucleus is labelled CM)
• Schiff N, Plum F (2000). "The role of arousal and "gating" systems in the neurology of impaired consciousness". Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society 17 (5): 438-52.
• Henderson J, Carpenter K, Cartwright H, Halliday G (2000). "Loss of thalamic intralaminar nuclei in progressive supranuclear palsy and Parkinson's disease: clinical and therapeutic implications". Brain 123 (Pt 7) 1410-21.
• Joe Bogen's Consciousness Page (Professor Bogen) at California Institute of Technology

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Last updated on Monday October 01, 2007 at 09:01:43 PDT (GMT -0700)
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