In healthy adult tissue TrkC.T1 is low or undetectable, but it is significantly upregulated shortly after injury, but before degeneration and detectable symptoms, in neurodegenerative diseases such as glaucoma, RP, and ALS (Bai et al., 2010b; Brahimi et al., 2016; Galán et al., 2017b), as well as in noise-induced hearing loss (Saragovi, unpublished). This evidence concerns the gene NTRK3 and retinitis pigmentosa 1.