Caudal colliculus

The caudal colliculus is a structure of the midbrain tectum composed of gray matter, located caudally, which receives auditory afferents from the lateral lemniscus, the medial geniculate body, the auditory cortex, and the cerebellum. It projects to the medial geniculate body, the nuclei of the lateral lemniscus, the cerebellum, and the rostral colliculus, and is involved in reflexive orientation toward auditory stimuli.

The brachium of caudal colliculus ensures the transmission of these auditory afferents to the thalamus and other relay centers, contributing to the integration and coordination of auditory reflexes.

In equids, the caudal colliculi are clearly smaller than their rostral counterparts, much shorter but elongated. In ruminants, they are more prominent and slightly more widely spaced. In carnivores, they are very prominent and extend on each side over the rostral colliculi. In humans, the caudal colliculi are relatively small and have almost the same volume as the rostral ones.