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Updated: Jul 15, 2026
Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates
Published on: January 30, 2014
Entry and distribution of microglial cells in human embryonic and fetal cerebral cortex
Anne Monier1, Homa Adle-Biassette, Anne-Lise Delezoide
1Institut National de la Santé et de la Recherche Médicale U676, Paris, France.
Abstract:
Microglial cells penetrate into and scatter throughout the human cortical grey and white matter according to a specific spatiotemporal pattern during the first 2 trimesters of gestation. Routes of entry were quantitatively and qualitatively different from those identified in the diencephalon. Starting at 4.5 gestational weeks, amoeboid microglial cells, characterized by different antibodies as Iba1, CD68, CD45, and MHC-II, entered the cerebral wall from the ventricular lumen and the leptomeninges. Migration was mainly radial and tangential toward the immature white matter, subplate layer, and cortical plate, whereas pial cells populated the prospective layer I. The intraparenchymal vascular route of entry was detectable only from 12 gestational weeks. Interestingly, microglial cells accumulated in restricted laminar bands particularly at 19 to 24 gestational weeks among the corona radiata fibers rostrally, extending caudally in the immature white matter to reach the visual radiations. This accumulation of proliferating MIB1-positive microglia (as shown by MIB1-Iba1 double immunolabeling) was located at the site of white matter injury in premature neonates. The spatiotemporal organization of microglia in the immature white and grey matter suggests that these cells may play active roles in developmental processes and in injury to the developing brain.
Insights
Microglia migrate through the developing human brain in a specific pattern during gestation. Their distribution suggests roles in both normal brain development and injury in premature infants.
Area of Science:
- Neuroscience
- Developmental Biology
- Immunology
Background:
- Microglia are the primary immune cells of the central nervous system.
- Understanding microglial development and migration is crucial for comprehending brain development and disease.
Purpose of the Study:
- To investigate the spatiotemporal pattern of microglial cell entry and distribution in the developing human brain during the first two trimesters of gestation.
- To identify the routes of microglial migration and their potential roles in developmental processes and white matter injury.
Main Methods:
- Immunohistochemistry using antibodies for Iba1, CD68, CD45, MHC-II, and MIB1.
- Quantitative and qualitative analysis of microglial cell entry and distribution in human cortical grey and white matter at different gestational ages.
Main Results:
- Microglial cells enter the cerebral wall from the ventricular lumen and leptomeninges starting at 4.5 gestational weeks.
- Migration follows radial and tangential routes, with distinct patterns for different microglial populations.
- Accumulation of proliferating microglia observed in specific white matter regions, coinciding with sites of injury in premature neonates.
Conclusions:
- Microglial cells exhibit a defined spatiotemporal organization within the developing human brain.
- These findings suggest microglia actively participate in neurodevelopmental processes.
- Microglial distribution patterns may indicate their involvement in white matter injury in premature infants.
