Mammillothalamic tract

The mammillothalamic tract (also mammillary fasciculus, mammillothalamic fasciculus, thalamomammillary fasciculus, bundle of Vicq d’Azyr) is an efferent pathway of the mammillary body which projects to the anterior nuclei of thalamus. It consists of heavily myelinated fibres. It is part of a brain circuit involved in spatial memory.

It arises from (the medial and lateral nuclei of) the mammillary body and from fibers that are directly continued from the fornix. It connects the mammillary body to the dorsal tegmental nuclei, the ventral tegmental nuclei, and the anterior thalamic nuclei.