In the pseudostratified neuroepithelium or ventricular zone (NE/VZ) of developing mammalian cerebral cortex, each neural progenitor cell shows nuclear movement along the apical-basal axis correlated with cell cycle called interkinetic nuclear migration (INM). While cell-autonomous molecular mechanisms were reported to be essential for INM, it was recently suggested that cell-to-cell physical interaction also play important role, especially for apical-to-basal INM of G1 cells. How INM of each progenitor cell is three-dimensionally coordinated to maintain the whole structure of the NE/VZ, however, still remains largely unknown. To answer the question, we performed carefully observed the dynamics of neural progenitor cells around periventricular area. We found that the onset of apical-to-basal INM of the newborn G1 nuclei from the periventricular area was not always correlated with the presence of neighboring cellbodies. A mathematical simulation for INM as a group also suggested that cellbody-cellbody physical interaction is not sufficient for the apical-to-basal INM of newborn G1 cells. We also found that morphological alternation of late G2, M and early G1 cells including basal process, cellbody and surrounding apical processes of neighboring cells are correlated with the onset of apical-to-basal INM. These observations suggest the existence of a novel mode of INM for newborn G1 cells, which may play critical roles for the maintenance of the characteristic structures of NE/VZ.

研究助成：Research funds : KAKENHI(22111001)