5-HT1A receptor-mediated activation of outward potassium current by serotonin in mouse cultured spiral ganglion neurons.

Cochlear spiral ganglion neurons provide the only pathway for transmitting sound evoked activity from the hair cells to the central auditory system. Serotonin plays a role in the response properties of central auditory neurons. However, knowledge about the role of serotonin in the peripheral auditory nervous system remains limited. In the current study, we investigated the influence of serotonin on outward potassium current in mouse cultured spiral ganglion neurons using whole-cell patch clamp technique. The cell capacitance was 4.03 ± 0.18 pF (n = 54). Application of serotonin caused an increase of outward potassium currents within seconds, whereas treatment with WAY100635, a selective 5-HT1A receptor antagonist, counteracted the increase effect of serotonin. These results suggest that serotonin increases outward potassium currents in cultured spiral ganglion neurons through the activation of 5-HT1A receptor. Serotonin may play an important role in sound transmission.