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Updated: Dec 25, 2025
Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates
Published on: January 30, 2014
Transient microglial absence assists postmigratory cortical neurons in proper differentiation
Yuki Hattori1,2, Yu Naito3, Yoji Tsugawa4,5,6
1Department of Anatomy and Cell Biology, Graduate School of Medicine, Nagoya University, Nagoya, Japan. ha-yuki@med.nagoya-u.ac.jp.
Abstract:
In the developing cortex, postmigratory neurons accumulate in the cortical plate (CP) to properly differentiate consolidating subtype identities. Microglia, despite their extensive surveying activity, temporarily disappear from the midembryonic CP. However, the mechanism and significance of this absence are unknown. Here, we show that microglia bidirectionally migrate via attraction by CXCL12 released from the meninges and subventricular zone and thereby exit the midembryonic CP. Upon nonphysiological excessive exposure to microglia in vivo or in vitro, young postmigratory and in vitro-grown CP neurons showed abnormal differentiation with disturbed expression of the subtype-associated transcription factors and genes implicated in functional neuronal maturation. Notably, this effect is primarily attributed to interleukin 6 and type I interferon secreted by microglia. These results suggest that "sanctuarization" from microglia in the midembryonic CP is required for neurons to appropriately fine-tune the expression of molecules needed for proper differentiation, thus securing the establishment of functional cortical circuit.
Insights
Microglia temporarily leave the developing cortical plate, attracted by CXCL12. Their absence is crucial for proper neuron differentiation and functional circuit formation, as their presence disrupts neuronal maturation.
Area of Science:
- Neuroscience
- Developmental Biology
- Immunology
Background:
- Postmigratory neurons in the developing cortex differentiate within the cortical plate (CP).
- Microglia, immune cells, transiently disappear from the midembryonic CP, but the reasons and consequences are unclear.
Purpose of the Study:
- To investigate the mechanism behind microglial absence from the midembryonic CP.
- To determine the significance of this microglial absence for neuronal development and cortical circuit formation.
Main Methods:
- Utilized in vivo and in vitro models to study microglial migration and neuronal differentiation.
- Analyzed the role of CXCL12 in microglial migration.
- Assessed the impact of microglia-derived factors (IL-6, type I interferon) on neuronal differentiation.
Main Results:
- Microglia migrate out of the midembryonic CP, attracted by CXCL12 from the meninges and subventricular zone.
- Excessive microglial presence in the CP leads to abnormal neuronal differentiation and disturbed gene expression.
- Interleukin 6 and type I interferon secreted by microglia are key mediators of this abnormal differentiation.
Conclusions:
- Microglial "sanctuarization" in the midembryonic CP is essential for precise neuronal differentiation.
- This absence allows neurons to fine-tune molecular expression for proper maturation.
- Ensures the establishment of functional cortical circuits by preventing microglial interference.
