The early fetal development of human neocortical GABAergic interneurons.
Bottom Line: CALB2-positive cells increased steadily in the SVZ/VZ from 10 PCW but were not double-labeled with Ki-67.Expression of GABAergic genes was generally higher in the dorsal pallium than in the ganglionic eminences, with lower expression in the intervening ventral pallium.It is widely accepted that the cortical proliferative zones may generate CALB2-positive interneurons from mid-gestation; we now show that the anterior neocortical proliferative layers especially may be a rich source of interneurons in the early neocortex.
Affiliation: Institute of Neuroscience Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK.Show MeSH
Related in: MedlinePlus
Mentions: Whole sagittal sections of fetal brain were also successfully immunostained for 4 markers of GABAergic interneurons, DLX2, ASCL1, GAD2, and CALB2 between 8 and 12 PCW weeks. At all stages, a similar expression pattern was observed for DLX2, ASCL1, and GAD2, with moderate expression in the GE, but stronger expression in the CP (Fig. 4). There was also some expression in the VZ/SVZ when compared with areas of completely negative staining in the diencephalon. CALB2 showed a different pattern of staining. CALB2-positive neurons were present in the postmitotic layers of the lateral (Fig. 5B,C) and caudal (not shown) GE, but were absent from the MGE (Fig. 4D). In the cortex, CALB2-positive neuronal cell bodies were prominent in the cortical plate (CP) at 8–9 PCW, with fewer also present in the marginal zone and subplate, but with many immunoreactive fibers present in the subplate and intermediate zone (Figs 4D and 5B). No immunostaining was present in the proliferative zones at these earlier stages.Figure 4.
Affiliation: Institute of Neuroscience Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK.