Inferior colliculus

The inferior colliculi ( " lower hillock ", singular inferior colliculus, caudal colliculus in animals - " rear hillock ', from Latin collis ' hill' ), the two lower ( rear ) hill of the midbrain roof ( tectum of midbrain ). Together with the upper hills ( superior colliculus ), they form the quadrigeminal plate ( or lamina quadrigeminal tecti ).

The nerve cells (neurons ) of the inferior colliculi receive excitatory and inhibitory impulses from neurons of the deeper nuclei of the auditory pathway ( including some from the cochlear nucleus and the superior olivary nucleus ), as well as back-projections of the auditory cortex. The central regions of the inferior colliculi have a tonotopic organization, with the frequency axis from dorsal ( low frequency ) to ventral ( high frequencies) runs.

The nerve fibers that come from the lateral lemniscus to reach the inferior colliculi and pull it over the brachium of the inferior colliculus to the medial geniculate body, part of the metathalamus. Here they are interconnected to the last ascending neurons, now draw their fibers to the temporal gyri transverse processes.

Since the fibers crossed to the part and run uncrossed, it comes with a one-sided inferior colliculus of the damage to a reduction of hearing the other side, but not to complete hearing loss.

• Mesencephalon