Fig 4.

Selected images illustrating the hippocampal-thalamic pathways. Coronal, sagittal, oblique axial (the dashed line in B represents the oblique imaging plane for C), and magnified coronal images of the fornix (9) and mammillothalamic tract (10). A and B, The decreased size of the postcommissural fornix as it approaches the mammillary bodies (56) is likely due, in part, to the direct hippocampal pathway (36) in C, which bypasses the mammillary bodies to reach the anterior thalamic nuclei (41). D, Just medial to the Fields of Forel (78) and pallidofugal tracts, the principal mammillary tract (80) gives rise to the ascending mammillothalamic tract. Note the subthalamic fasciculus (81) and zona incerta (asterisk).