Differentiation of Neural Cells in the Fetal Cerebral Cortex of Cynomolgus Monkeys (Macaca fascicularis)

摘要

ProliferationandprogrammedcelldeathareimportantintheformationofmorphologicstructuresandfunctionalactivityduringCNSdevelopment.WeusedimmunohistochemicalandTUNELmethodstoexaminetheproliferationanddifferentiationofneuralcellsin,distributionofapoptoticcellsin,andmicroglialcellinvolvementintheremovalofapoptoticcellsfromthefetalcerebralcortexofcynomolgusmonkeys.Atembryonicday(E)50andE80,theneuroepitheliumcontainedmanymitoticcells.CellsstainingforPCNA(anuclearmarkerofproliferatingcells)wereprominentintheproliferativezone,whereascellspositiveforNeuN(aneuron-specificmarker)wereabsent.GFAPstainingforglialcellswaspositiveintheneuroepitheliumandradialglialfibers.Iba1-positivecells(thatis,macrophagesandmicroglia)weredistributedthroughoutallregionsatalltimepointsbutaccumulatedespeciallyintheventricularzoneatE80.Apoptoticmorphology(atE80)andTUNEL-positivecells(thatis,containingDNAfragmentation;atE50andE80)wereobservedalso.AtE120andE150,mostPCNA-positivecellswereintheventricularzone,andNeuN-positivecellswereprominentinalllayersexceptlayerI-IIatE120.GFAPimmunoreactivitywasdetectedmainlyincellswithfineprocessesinthewhitematter.NeitherapoptosisnorTUNEL-positivecellsweredetectedateitherE120orE150.Theseresultssuggestthatproliferation,migration,andneuralcelldeathoccurduringmidgestation(thatis,E50toE80)infetalbrainofcynomolgusmacaques,whereasdifferentiationandmaturationofneuralcellsoccuraftermidgestation(E80).