BDNF and Alzheimer disease: Other chemicals used to induce AD in laboratory animals include D-galactose, which impairs learning and memory through several mechanisms, (including increasing oxidative stress, suppressing production of brain derived neurotrophic factor, hyperphosphorylation of extracellular signal regulated kinases and cAMP response element-binding protein), which mediate long term memory and other synaptic functions (Um et al., 2018).