Mammillary bodies

Mammillary body
The hypophysis cerebri in position. Shown in sagittal section. (Label "corpus mamillare" at right.)
Coronal section of brain through intermediate mass of third ventricle. (Label "corpora mamillaria" at bottom.)
Details
Part of	Diencephalon
System	Limbic
Components	medial mammillary nucleus lateral mammillary nucleus
Identifiers
Latin	Corpus mamillare (Plural: Corpora mamillaria)
Acronym(s)	mmb
MeSH	A08.186.211.730.385.357.362.500
NeuroNames	hier-395
NeuroLex ID	Mammillary body
TA	A14.1.08.402
FMA	74877
Anatomical terms of neuroanatomy []

The mammillary bodies are a pair of small round bodies, located on the undersurface of the brain that, as part of the diencephalon, 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.

Neuroanatomists have often categorized the mammillary bodies as part of the hypothalamus.

It was previously also known as corpus albicans, but later this term became obsolete due to the degenerated corpus luteum also being called so.

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.

Mammillary bodies, and their projections to the anterior thalamus via the mammillothalamic tract, are important for recollective memory. The medial mammillary nucleus is mainly responsible for the spatial memory deficits that are seen in rats with mammillary body lesions.

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.