The nucleus of the trochlear nerve is located in the midbrain, at an intercollicular level between the superior colliculus and inferior colliculus.[1] It is a motor nucleus, and so is located near the midline, embedded within the medial longitudinal fasciculus (see diagram at right). The oculomotor nerve and trochlear nerve are the only two cranial nerves with nuclei in the midbrain, other than the trigeminal nerve, which has a midbrain nucleus called the mesencephalic nucleus of trigeminal nerve, which functions in preserving dentition.