Figure 2.

Schematics of the MOC System. (A) MOC efferent neurons are located in the superior olivary complex of the brainstem and project to the cochlea; (B) MOC fibers make direct synaptic contacts at the base of the OHCs; (C) At the MOC-OHC synapse ACh is released. It binds to α9α10 nAChRs present at the OHCs, leading to Ca²⁺- influx and the subsequent activation of Ca²⁺-dependent K⁺ (SK2) channels and hair cell hyperpolarization. The white arrow in (B) indicates the afferent fibers that bring the information from the IHCs to the central nervous system, and the red arrow indicates the MOC fibers. Reproduced from Taranda et al (2009)¹² under Creative Commons Attribution (CC BY) license.