BDNF and Alzheimer disease: Of noteworthy significance, AD shows an imbalance in specific paralleling neurotrophic factors and receptors, and the same is indirectly seen in ARHL, where BDNF proteins are drastically reduced in peripheral and central auditory projections [114] and BDNF and tropomyosin receptor kinase B (TrkB)-agonists improve SGN survival [124].