NGF and Alzheimer disease: In addition, a reduced availability of NGF has also been found to contribute to AD: an impairment of NGF maturation from its precursor proNGF causes the vulnerability of cholinergic neurons in AD [28], [29], [30]; deprivation of NGF leads to AD-like pathologies such as Aβ accumulation/deposition, tau hyperphosphorylation, synaptic dysfunction and memory deficits in mice [31], [32]; and administration of NGF can ameliorate Aβ pathologies and prevent memory deficits in AD animal models [33], [34].