The diencephalon is the second part of the forebrain located in the midline. It contains the third ventricle and connects the cerebrum to the midbrain. The diencephalon is divided into dorsal and ventral parts by the hypothalamic sulcus. The dorsal part contains the thalamus, metathalamus, and epithalamus, while the ventral part contains the hypothalamus and subthalamus. The thalamus is the largest structure in the dorsal diencephalon and relays sensory and motor information to the cerebral cortex. It contains several nuclei that process different sensations and pathways. The metathalamus contains the medial and lateral geniculate bodies which