The LHA receives the strongest field CA1 projection of any hypothalamic component. LHA medial regions receive a moderate projection of varicose fibers and terminal boutons from the rostral end of the LHA to about mid-rostrocaudal levels of the ventromedial nucleus, where the projection becomes considerably denser (Fig. 3D-G).

Rostroventrally, a tight group of PHAL-labeled fibers is observed in the ventromedial corner of the LHA anterior region’s ventral zone, and a few labeled fibers are also seen in the intermediate zone (Fig. 3D-F).

Rostrodorsally, a moderate plexus of varicose fibers with boutons occupies the LHA juxtaparaventricular region and an adjacent medial expanse of the anterior region’s dorsal zone, dorsal to the anterior hypothalamic nucleus (Fig. 3E,F).

At the level of the ventromedial nucleus, the terminal field becomes significantly denser (Fig. 3G). Here, the LHA’s juxtadorsomedial region, and dorsal and ventral zones of the juxtaventromedial region, all contain a moderately dense terminal field.