MAPT and Alzheimer disease: Transduction of the brains of newborn rats with adeno associated virus serotype 1 vector carrying human I2CTF (53) or I2NTF and I2CTF transgenes was found to induce AD-like abnormal hyperphosphorylation and aggregation of tau, a loss of neuronal plasticity, and cognitive impairment in these animals at 5–12 months post-infection (54); however, no neurofibrillary tangles or Aβ plaques were detected in the brains of AAV1-I2NTF-CTF rats up until 13 months.