SLC12A5 and Tinnitus: Regarding the possible contribution of KCC2 down-regulation in some neurological diseases, including neuropathic pain [which is often compared to tinnitus – (Møller, 2007)], and the dramatic decrease of KCC2 after cochlear nerve section (this study), it is tempting to propose that down-regulation of KCC2 after hearing loss may play a role in the generation of tinnitus and hyperacusis.