MAPT and Alzheimer disease: Moreover, direct responses to Aβ and tau deposition are inflammation and a decline in the immune system, which also play very important roles in AD development [7], by the stimulation of microgliosis and astrogliosis, mitochondrial dysfunction, oxidative stress, excitotoxicity, etc., with concomitant loss of synapses and neurons, a progressive decline in cognitive performance, and robust memory loss.