Unique Morphological Features of the Proliferative Zones and Postmitotic Compartments of the Neural Epithelium Giving Rise to Striate and Extrastriate Cortex in the Monkey

We examined the development of the occipital lobe in fetal monkeys between embryonic day 37 (E37) and E108 in Nissl-stained and acetylcholine esterase (AChE)-reacted sections. We paid particular attention to features that distinguish the development of presumptive area 17. At E46 the neuroepithelium consists of a ventricular zone and a monolayer cortical plate sandwiched between a thin marginal zone and a minimal presubplate. Between E55 and E65 an augmented subplate emerges and continues to expand up to E94 to become a major compartment of the developing cortex. A mitotic subventricular zone is established by E55. Peaking in depth at E72, it constitutes the principal germinal zone. By E78 an invading fibre…