- Knockdown of amyloid precursor protein normalizes cholinergic function in a cell line derived from the cerebral cortex of a trisomy 16 mouse: An animal model of down syndrome. Opazo, P., Saud, K., de Saint Pierre, M., C??rdenas, A.M., Allen, D.D., Segura-Aguilar, J., Caviedes, R., Caviedes, P. J. Neurosci. Res. (2006)