Thehyperpallium (formerly called thehyperstriatum or thewulst[1]) is the destination forlemnothalamic projections inbirds. The projections as well as thegranular cells at the destination of the lemnothalamic projections to the hyperpallium are similar in morphology,electrophysiology,retinotopic organization, and columnar organization to thestriate cortex in mammals. These avian granular cells are thought to have evolved independently in birds, as they do not appear inreptiles.
The projections originate in the dorsallateral geniculate nucleus and target three layers in the hyperpallium: the hyperpallium intercalatum, the hyperpallium densocellularis, and the nucleus interstitialis hyperpalii apicalis, with the densest projections being to the later two layers.
Theefferents of the telencephalic components of the lemnothalamic pathway project to theoptic tectum (equivalent to the superior colliculus), the lemnothalamic visual nucleus, as well as other optic tract targets.
The hyperpallium is observed to be large and well developed inraptors such aseagles,hawks, andowls.[2]