L.  Gu, Kleiber, S., Schmid, L., Nebeling, F., Chamoun, M., Steffen, J., Wagner, J., and Fuhrmann, M., ?Long-Term In Vivo Imaging of Dendritic Spines in the Hippocampus Reveals Structural Plasticity?, vol. 34, pp. 13948?13953, 2014.