“…In three-dimensional environments, cell production via mitosis depends not only on the progression of the cell cycle but also on the movement of cells' nuclei/somata into place for mitosis, making the overall cell-production events highly temporally and spatially dynamic (Keller, Schmidt, Wittbrodt, & Stelzer., 2008;Kurotaki, Hatta, Nakao, Nabeshima, & Fujimori, 2007;Miyata, 2008;Norden, Young, Link, & Harris, 2009;Taverna & Huttner, 2010). Recent studies using slice culture-based imaging and mechanical assessment of developing mammalian brain walls have shown that such dynamic cytogenetic events occur at a very high density under physiologically crowded cellular conditions (Miyata, Okamoto, Shinoda, & Kawaguchi, 2015;Nagasaka et al, 2016;Okamoto et al, 2013;Okamoto, Shinoda, Kawaue, Nagasaka, & Miyata, 2014;Saito, Kawasoe, Sasaki, Kawaguchi, & Miyata, 2018;Shinoda et al, 2018); the studies also show that delays in the cell cycle or nuclear migration in a subpopulation of progenitors can easily lead, in a cell non-autonomous manner, to secondary (more widespread) disorganization of histogenesis (Okamoto et al, 2013;Watanabe, Kawaue, & Miyata, 2018).…”