The degeneration of SGN in SNHL was considered to be a consequence of absence of neurotrophic factor from the hair cells, which is supported by many other studies showing that the ultrastructural changes and loss of SGNs in SNHL could be attenuated by the application of BDNF or NT-3 (Staecker et al., 1996; Richardson et al., 2005; Shepherd et al., 2005; Agterberg et al., 2008; Landry et al., 2011; Fukui et al., 2012; van Loon et al., 2013). Here, BDNF is linked to sensorineural hearing loss disorder.