Dynamic expression of calretinin in embryonic and early fetal human cortex.

摘要: Calretinin (CR) is one of the earliest neurochemical markers in human corticogenesis. In embryos from Carnegie stages (CS) 17 to 23, calbindin (CB) and CR stain opposite poles incipient cortex suggesting early regionalization: CB marks neuroepithelium medial boundary with choroid plexus (cortical hem). By contrast, confined subventricular zone (SVZ) lateral caudal ganglionic eminences at pallial-subpallial (PSB, or antihem), where CR+/Tbr1- neurons migrate toward piriform amygdala as a component cortical stream. At CS 19, columns CR+ cells arise rostral cortex, contribute 20 “monolayer” horizontal Tbr1+/CR+ GAD+ preplate. 21, “pioneer plate” appears radial aggregation CR+/Tbr1+ neurons, which cover entire future neocortex extend first corticofugal axons. expression corticogenesis thus not restricted interneurons, but also present excitatory projection cortex. 21/22, plate established following gradient, when Tbr1+/CR- settle within pioneer plate, separate superficial deep neurons. disappear shortly after formation plate. Reelin+ Cajal-Retzius begin express around CS21 (7/8 PCW). 21-23, SVZ PSB source interneurons migrating into SVZ. turn, CB+ subpallium intermediate fibers internal capsule. Early have different origins migratory routes. cell populations embryonic telencephalon take part complex sequence events analyzed so far other mammalian species, may represent distinctive trait initial steps