Table 2.

Description of measured morphological and proliferative features per cell

Feature	Description	Possible values
Morphology at birth	Presence/absence of apical/basal processes at birth	• No processes • Apical process only • Basal process only • Apical and basal process
Morphology at mitosis	Presence/absence of apical/basal processes prior to mitosis	• No processes • Apical process only • Basal process only • Apical and basal process
Cell type	Cycling/postmitotic	• Unknown • Cycling • Postmitotic • Dead cell
Process stability	Process stability between birth and mitosis	• No process • Minimum one transient process • Permanent (at least one process during at least 85% of the cell's lifetime)
Process retraction	Retraction of processes during mitosis	• No mitosis • No retraction • Minimum one process retracts
Cell‐cycle length	Cell‐cycle length in hours	• No mitosis • Time bins for 20–40, 40–60, 60–80, 80–100 h
Mitotic plane angle	Orientation of mitotic plane	• No mitosis • 0–30, 30–60, 60–90 deg
Translocation	Translocation movement prior to mitosis	• No mitosis • Downward translocation • No translocation • Upward translocation
Zone	Zone where cell is located at onset	• Apical VZ (ventricular zone) • ISVZ (inner subventricular zone) • IFL (inner fiber layer) • OSVZ (outer subventriculsar zone) • OFL (outer fiber layer) • SP (subplate)
Mitosis location	Cell following mitosis	• Lower daughter cell • Upper daughter cell
Division type	Proliferative or differentiative division: the values indicate the daughter cell types (proliferative, postmitotic, unknown type)	• Absence of mitosis • 2 postmitotic • 1 postmitotic, 1 unknown • 1 postmitotic, 1 proliferative • 1 proliferative, 1 unknown • 2 proliferative • unknown