Table 5.

Stage comparison between chick, mouse, and human at pre-neuronal stages of embryonic CNS development. Comparison between chick (HH), mouse, (E), and human (days, weeks) embryonic stages is shown for neural plate formation, neurulation (i.e. formation of the neural folds), and brain primordia formation (i.e. formation of the forebrain, midbrain and hindbrain vesicles). The data is compiled from Carnegie Stages Comparison^[132] and Psychoyos et al.^[133]

Species	Neural plate		Neurulation		Brain primordia
Chick (HH)	4	5	8	10	11	12	13
Mouse (E)	7	7.25	7.5	7.75	8	8.25	9
Human (days)	16	18	20	21	22	24	28
Human (wks)	2	2.5	2.5	3	3	3.5	4