Start your One-Week Free Trial
Already subscribed? Log in »
Central Auditory Pathways
COCHLEAR NUCLEI
- The ventral cochlear nucleus lies at the pontomedullary junction along the ventrolateral surface of the restiform body of the inferior cerebellar peduncle.
- It is often divided into anterior and posterior subnuclei.
- The dorsal cochlear nucleus lies in the upper medulla along the dorsolateral surface of the restiform body of the inferior cerebellar peduncle.
- Lies in the mid-pons.
- Bilateral: each superior olivary complex comprises three separate nuclei - a nucleus of the trapezoid body, medial superior olivary nucleus, and lateral superior olivary nucleus.
- Surrounding the superior olivary complexes are peri-olivary cells.
- Lateral lemniscus tract - projection from the superior olivary complex to the inferior colliculus.
- Brachium of the inferior colliculus - projection from the inferior colliculus to the ipsilateral medial geniculate nucleus (part of the metathalamus).
- Projection exists from the medial geniculate nucleus to the ipsilateral transverse temporal gyri (Heschl's gyri, the primary auditory cortex) - continuous with the superior temporal gyrus in the Sylvian fissure.
- Projections from the ventral and dorsal cochlear nuclei.
- Ventral stria (aka trapezoid body) - Passes ventral to the restiform body.
- Projections - 1) unilateral ventral cochlear nucleus to the bilateral superior olivary complexes, 2) ventral cochlear nucleus to the contralateral inferior colliculus via the lateral lemniscus (no synapse in the superior olivary complex).
- Dorsal acoustic stria - passes dorsally around the restiform body.
- Projection - dorsal cochlear nucleus projects to the contralateral inferior colliculus via the lateral lemniscus (no synapse in the superior olivary complex).
- Intermediate acoustic stria - passes dorsally around the restiform body.
- Projection - dorsal portion of the ventral cochlear nucleus projects to the contralateral inferior colliculus via the lateral lemniscus tract (no synapse in the superior olivary complex).
S-L-I-M
Key steps in the pathway:
- Superior olivary complex ->
- Lateral lemniscus ->
- Inferior colliculus ->
- Medial geniculate body