The mammillothalamic tract (mammillothalamic fasciculus, thalamomammillary fasciculus, bundle of Vicq d’Azyr) arises from cells in both the medial and lateral nuclei of the
mammillary body
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 ...
and by fibers that are directly continued from the
fornix Fornix (plural ''fornices'', Latin for "arch") can refer to:
*''Fornix'' or ''throat scale'', a bowed prolongation of the corolla
Corolla may refer to:
*Corolla (botany), the petals of a flower, considered as a unit
*Toyota Corolla, an automobile ...
.
The mammillothalamic tract then connects the
mammillary body
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 ...
to the
dorsal tegmental nuclei, the
ventral tegmental nuclei, and the
anterior thalamic nuclei
The anterior nuclei of thalamus (or anterior nuclear group) are a collection of nuclei at the rostral end of the dorsal thalamus. They comprise the anteromedial, anterodorsal, and anteroventral nuclei.
Inputs and outputs
The anterior nuclei rec ...
.
[
]
Structure
The mammillothalamic tract was first described by the French physician, Félix Vicq d'Azyr
Felix may refer to:
* Felix (name), people and fictional characters with the name
Places
* Arabia Felix is the ancient Latin name of Yemen
* Felix, Spain, a municipality of the province Almería, in the autonomous community of Andalusia, S ...
, from whom it takes its alternate name (bundle of Vicq d'Azyr). There, axons divide within the gray matter; the coarser branches pass into the anterior nucleus of the thalamus as the ''bundle of Vicq d’Azyr''. The finer branches pass downward as the mammillotegmental ''bundle of Gudden''.[ The bundle of Vicq d’Azyr spreads fan-like as it terminates in the ]medial dorsal nucleus
The medial dorsal nucleus (or dorsomedial nucleus of thalamus) is a large nucleus in the thalamus.
It is believed to play a role in memory.
Structure
It relays inputs from the amygdala and olfactory cortex and projects to the prefrontal cortex a ...
.[ Some fibers pass through the dorsal nucleus to the angular nucleus of the thalamus. ("The term 'angular thalamic nucleus' refers to a group of cells ventral to the lateral dorsal nucleus of thalamus."][NeuroNames. Angular Thalamic Nucleus --]
"What, Where and How Big is It?"
BrainInfo. Accessed January 25, 2011.). The axons from these nuclei form part of the thalamocortical radiations
In neuroanatomy, thalamocortical radiations are the fibers between the thalamus and the cerebral cortex.
Structure
Thalamocortical (TC) fibers have been referred to as one of the two constituents of the isothalamus, the other being micro neuron ...
.
Function
The mammillary bodies directly or indirectly connect to the amygdala
The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex v ...
, hippocampus
The hippocampus (via Latin from Greek , ' seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, ...
, and thalami
The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, ...
as major structures in the limbic system
The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain.Schacter, Daniel L. 2012. ' ...
.[ The mammillothalamic tract carries signals from the mammillary bodies via the anterior thalamus to support ]spatial memory
In cognitive psychology and neuroscience, spatial memory is a form of memory responsible for the recording and recovery of information needed to plan a course to a location and to recall the location of an object or the occurrence of an event. Sp ...
.[
]
Clinical significance
Infarction
Infarction is tissue death (necrosis) due to inadequate blood supply to the affected area. It may be caused by artery blockages, rupture, mechanical compression, or vasoconstriction. The resulting lesion is referred to as an infarct
(from the ...
of the region including the mammillothalamic tract has been associated with alcoholic Korsakoff syndrome
Korsakoff syndrome (KS) is a disorder of the central nervous system characterized by amnesia, deficits in explicit memory, and confabulation. This neurological disorder is caused by a deficiency of thiamine (vitamin B1) in the brain, and it is ...
.
See also
* Hypothalamotegmental tract In human neuroanatomy, the hypothalamotegmental tract is a pathway from the hypothalamus to the reticular formation. Axons from the posterior hypothalamus descend through the mesencephalic and pontine reticular formations. They connect with reticu ...
* Papez circuit
References
External links
* - "mammillothalamic tract"
** - "mammillothalamic tract of hypothalamus"
** - "mammillothalamic tract of thalamus"
* https://web.archive.org/web/20080505050804/http://isc.temple.edu/neuroanatomy/lab/atlas/dan2/
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Limbic system
Thalamic connections