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Mammillary body

Brain: Mammillary body
Gray1180.png
The hypophysis cerebri in position. Shown in sagittal section. (Label "corpus mamillare" at right.)
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Coronal section of brain through intermediate mass of third ventricle. (Label "corpus mamillare" at bottom.)
Latin corpus mamillare
Gray's subject #188 813
Part of Midbrain
System Limbic
Components medial mammillary nucleus
lateral mammillary nucleus
Acronym(s) mmb
NeuroNames hier-395
MeSH Mamillary+Bodies
NeuroLex ID birnlex_865

The mammillary bodies (mamillary bodies) are a pair of small round bodies, located on the undersurface of the brain, that form part of the limbic system. They are located at the ends of the anterior arches of the fornix. They consist of two groups of nuclei, the medial mammillary nuclei and the lateral mammillary nuclei.[1]
Neuroanatomists have often categorized the mammillary bodies as part of the hypothalamus.[2]

 Connections

They are connected to other parts of the brain (as shown in the schematic, below left), and act as a relay for impulses coming from the amygdalae and hippocampi, via the mamillo-thalamic tract to the thalamus.

This circuit, from amygdalae to mammillary bodies, and then on to the thalamus, is part of the larger 'Papez circuit'.

 Function

They, along with the anterior and dorsomedial nuclei in the thalamus, are involved with the processing of recognition memory.

They are believed to add the element of smell to memories.

 Pathology

The mammillary bodies are parts of the brain known to be significantly damaged by untreated Obstructive Sleep Apnea Hypoxia,and associated with deficiency of thiamine. Researchers, in 2008, also noted visible abnormalities in the mammillary bodies of individuals with Obstructive Sleep Apnea.[3]

Damage to the mammillary bodies due to thiamine deficiency is implied in pathogenesis of Wernicke-Korsakoff syndrome. Symptoms include impaired memory, also called anterograde amnesia, suggesting that the mammillary bodies may be important for memory. Lesions of the medial dorsal and anterior nuclei of the thalami and lesions of the mammillary bodies are commonly involved in amnesic syndromes in humans.[4]

 Additional images

 References

  1. ^ http://www.cf.ac.uk/psych/resources/vann2004.pdf Reference for the two groups of nuclei (not for the text before).
  2. ^ M.B. Carpenter and J. Sutin: Human Neuroanatomy (8th edition) 1983
  3. ^ - "The Auditory System: Anatomy and Maturation" at www.conradsimon.org
  4. ^ Duprez T, Serieh B, Raftopoulos C (01 Jan 2005). "Absence of memory dysfunction after bilateral mammillary body and mammillothalamic tract electrode implantation: preliminary experience in three patients". AJNR. American journal of neuroradiology 26 (1): 195–7; author reply 197–8. PMID 15661728. http://www.ajnr.org/cgi/content/full/26/1/195. 

 External links

 

The content of this section is licensed under the GNU Free Documentation License (local copy). It uses material from the Wikipedia article "Mammillary body" modified November 23, 2009 with previous authors listed in its history.