Scheme of auditory pathway

Scheme of neurones of auditory pathway. 4 neuronal afferent centripetal tract terminating in the primary acoustic cortex of temporal lobe. Receptor: hairs cells of Corti organ inside the membranous cochlear duct of inner ear. Receptors are surrounded by dendrites of bipolar neurons of the cochlear ganglion (1. N). Axons of bipolar neurons form the cochlear nerve. Cochlear nerve terminates in the cochlear nuclei (2. N) in the brainstem. From cochlear nuclei information go by the lateral lemniscus into the inferior collicle (3. N) in the mesencephalon. Signals interpolate in the inferior collicle and continue to the medial geniculate body (4. N). The last part of the auditory tract – acustic radiation (geniculo-cortical tract) continue into the upper part of the temporal lobe – transverse temporal gyruses (primary acustic cortex). Between the basic neurons of the auditory pathway there are inserted interstitial (relay neurons) which are grouped into independent nuclei : nucleus olivaris superior, nucleus corporis trapezoidei, nucleus lemnisci lateralis.

Term name Layer
1 1st neuron of auditory pathway Layer 1
2 2nd neuron of auditory pathway Layer 1
3 3rd neuron of auditory pathway Layer 1
4 4th neuron of auditory pathway Layer 1
5 Posterior cochlear nucleus; dorsal cochlear nucleus Layer 1
6 Anterior cochlear nucleus; ventral cochlear nucleus Layer 1
7 Superior olivary nucleus; superior olivary complex Layer 1
8 Lateral superior olivary nucleus Layer 1
9 Medial superior olivary nucleus Layer 1
10 Trapezoid body Layer 1
11 Base of peduncle Layer 1
12 Nuclei of inferior colliculus Layer 1
13 Medial geniculate body Layer 1
14 Temporal lobe Layer 1