ABSTRACT
The cochlear nuclei are a group of neurons in the brainstem that receive input from the auditory nerve fibers that originate in the cochlea. The bushy cells, located in the AVCN, receive input from the auditory nerve fibers and play a role in processing temporal information. The T-stellate cells and octopus cells, located in the PVCN, receive input from the bushy cells and play a role in processing spectral information. The unipolar brush cells and fusiform cells, located in the DCN, integrate multisensory information, including auditory and somatosensory input. The output from the DCN reaches the contralateral inferior colliculus directly. The second station in the auditory pathway is the superior olivary complex (SOC), which receives input from the auditory SGNs that reach out from the cochlear nuclei. The SOC consists of five to nine nuclei, including the medial nucleus of the trapezoid body (MNTB), the medial superior olive (MSO), the lateral superior olive (LSO), and the superior paraolivary nucleus (SPON). These nuclei play a role in sound localization and binaural hearing. The inferior colliculus (IC) is located immediately caudal to the superior colliculus (SC) of the midbrain and rostral to the cerebellum. The IC receives input from almost all cochlear nuclei, the SOC, and the lateral lemniscus (LL). The output from the IC is the almost sole source of the medial geniculate body (MGB), which reaches out to the auditory cortex. The auditory cortex (AC) receives fibers from the MGB and provides reciprocal feedback to the MGB. The AC is surrounded by 6 (in mice) to over 30 (in humans) areas that deal with associated auditory processing.
