Term: Thalamus

Definition: On embryological grounds the mammalian thalamus has most commonly been divided into epithalamus (note 224), dorsal thalamus (DOR), and ventral thalamus (Table A, note 30) (see Alvarez-Bolado and Swanson 1996). Dorsal thalamic nuclei project in a topographically organized way to virtually all parts of the cortical mantle, and are thought to develop more or less as a unit. We have chosen to represent the dorsal thalamus as a unit (divided into parts innervating predominantly sensory-motor related cortical areas, and parts innervating predominantly polymodal association related cortical areas) in this hierarchy because of the obvious topographic relationships displayed by its cortical projections-rather than attempting to distribute its various components to the various sensory and other modalities arranged below. The latter approach generates a more complex Table.

Nomenclature: Swanson-2004