Mammillothalamic fasciculus (bundle of Vicq d'Azyr) - Brain - Limbic lobe - e-Anatomy
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Mammillothalamic fasciculus (bundle of Vicq d'Azyr)

Fasciculus mammillothalamicus (Vicq d'Azyr)

  • Eponym: Vicq d'Azyr

Definition

Yasin Toudehzaim

The mammillothalamic fasciculus (MTF) is essentially a memory highway that connects the mammillary bodies to the anterior thalamus. It is a glutamatergic pathway, meaning it excites anterior thalamic neurons to propagate memory-related signals. Damage to this tract results in severe anterograde amnesia and is classically associated with Korsakoff syndrome.

Pathway Simplified

  • Origin: Medial and lateral mammillary nuclei.

  • Course: Axons ascend dorsally through the hypothalamus.

  • Bifurcation:

    • Thick fibers → Mammillothalamic fasciculus → Anterior thalamus.

    • Thin fibers → Mammillotegmental fasciculus → Brainstem reticular structures.

  • Termination: Fan-like distribution in the anterior thalamic nuclei (anteroventral and anteromedial).

Role in the Papez Circuit

Hippocampus →Fornix →Mammillary bodies →Mammillothalamic fasciculus →Anterior thalamic nuclei →Cingulate gyrus →Entorhinal cortex →Hippocampus

It can be considered the “middle link” that transmits hippocampal memory information via the mammillary bodies.

References

  • Hall JE. Guyton and Hall textbook of medical physiology. 14th ed. Philadelphia: Elsevier; 2021.

  • Saladin KS. Anatomy & physiology: the unity of form and function. 9th ed. New York: McGraw-Hill Education; 2021.

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