Mamillothalamic tract

The mammillothalamic fasciculus (mammillothalamic tract, thalamomammillary fasciculus, bundle of Vicq d’Azyr) arises from cells in both the medial and lateral nuclei of the mammillary body and by fibers that are directly continued from the fornix.

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 mammillo-tegmental bundle of Gudden.

The bundle of Vicq d’Azyr spreads out fan-like as it terminates in the anterior or dorsal nucleus of the thalamus.

A few of the fibers pass through the dorsal nucleus to the angular nucleus of the thalamus.

The axons from these nuclei are supposed to form part of the thalamocortical system.