title: Differentiation of neural cells in the fetal cerebral cortex of cynomolgus monkeys (Macaca fascicularis).
abstract: Proliferation and programmed cell death are important in the formation of morphologic structures and functional activity during CNS development. We used immunohistochemical and TUNEL methods to examine the proliferation and differentiation of neural cells in, distribution of apoptotic  cells in, and microglial cell involvement in the removal of apoptotic cells from the fetal cerebral cortex of cynomolgus monkeys. At embryonic day (E) 50 and E80, the neuroepithelium contained many mitotic cells. Cells staining for PCNA (a nuclear marker of proliferating cells) were prominent  in the proliferative zone, whereas cells positive for NeuN (a neuron-specific marker) were absent. GFAP staining for glial cells was positive in the neuroepithelium and radial glial fibers. Iba1-positive cells (that is, macrophages and microglia) were distributed throughout all regions at  all time points but accumulated especially in the ventricular zone at E80. Apoptotic morphology (at E80) and TUNEL-positive cells (that is, containing DNA fragmentation; at E50 and E80) were observed also. At E120 and E150, most PCNA-positive cells were in the ventricular zone, and NeuN-positive  cells were prominent in all layers except layer I-II at E120. GFAP immunoreactivity was detected mainly in cells with fine processes in the white matter. Neither apoptosis nor TUNEL-positive cells were detected at either E120 or E150. These results suggest that proliferation, migration, and  neural cell death occur during midgestation (that is, E50 to E80) in fetal brain of cynomolgus macaques, whereas differentiation and maturation of neural cells occur after midgestation (E80).
authors.affiliation: Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan. aa077150@mail.ecc.u-tokyo.ac.jp
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Toyoshima
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sekiguchi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Negishi
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Toshio
authors.initials: T
authors.lastname: Ihara
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ishii
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kyuwa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yoshikawa
authors.forename: Kimimasa
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology* / Q000196:embryology; D005333:Fetus / Q000196:embryology*; D007150:Immunohistochemistry / Q000662:veterinary; D020287:In Situ Nick-End Labeling / Q000662:veterinary; D008252:Macaca fascicularis / Q000196:embryology*; D009474:Neurons / Q000502:physiology*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism
chemical_list: D018809:Proliferating Cell Nuclear Antigen