Organ
Mammillary bodies
Hypothalamic nodes in the episodic-memory circuit
High-yield
A classic Papez route runs from hippocampus through fornix, mammillary bodies and mammillothalamic tract to anterior thalamus, then through cingulate and parahippocampal–entorhinal connections back toward the hippocampus.
Overview
The mammillary bodies are paired rounded structures visible on the inferior hypothalamic surface, behind the infundibular region. They receive hippocampal connections through the postcommissural fornix and send fibers to the anterior thalamic nuclei through the mammillothalamic tract. Their additional brainstem connections help make them active components of the memory network rather than a simple passive relay.
Reference facts
- Location
- Posteroinferior hypothalamus, on the brain's basal surface just anterior to the midbrain region
- Parts
- Medial and lateral mammillary nuclei on each side
- Blood supply
- Perforating branches from the posterior communicating and posterior cerebral arterial systems
- Relations
- Behind the tuber cinereum and anterior to the posterior perforated region; receive postcommissural fornix fibers and give rise to the mammillothalamic tract
- Function
- Participate in recollection and spatial-memory circuits through connections with hippocampal, thalamic and brainstem regions
Clinical correlation
Thiamine deficiency can damage mammillary bodies and other connected regions in Wernicke–Korsakoff disease. Persistent difficulty forming new memories may occur, sometimes with confabulation. The syndrome cannot be attributed to mammillary damage alone: thalamic nuclei and connecting pathways are also important.
Frequently asked questions
Where are the mammillary bodies located?
The mammillary bodies lie posteroinferior hypothalamus, on the brain's basal surface just anterior to the midbrain region.
What do the mammillary bodies do?
Participate in recollection and spatial-memory circuits through connections with hippocampal, thalamic and brainstem regions.
What are the parts of the mammillary bodies?
Medial and lateral mammillary nuclei on each side.
What is the blood supply of the mammillary bodies?
The mammillary bodies are supplied by the perforating branches from the posterior communicating and posterior cerebral arterial systems.