Telencephalon

The telencephalon is the outer region of the forebrain that surrounds the diencephalon, which is deeply located. It gives rise to the cerebrum that consists of two cerebral hemispheres. Each cerebral hemisphere has an overlying layer of gray matter called the cerebral cortex, which covers the subcortical white matter underneath, and also contains subcortical gray matter nuclei including the basal nuclei.

Unlike the telencephalon, the diencephalon, which is considered more primitive in terms of its evolutionary origin, includes various structures surrounding the third ventricle, such as the thalamus, hypothalamus, and subthalamus.