Thalamus

The thalamus (from Greek θάλαμος, "inner chamber") is a midline symmetrical structure within the brains of vertebrates including humans, situated between the cerebral cortex and midbrain. Its function includes relaying sensory and motor signals to the cerebral cortex, along with the regulation of consciousness, sleep, and alertness. The thalamus surrounds the third ventricle. It is the main product of the embryonic diencephalon.

Read more about Thalamus:  Anatomy, Function, Development, Pathology