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Updated: Jul 30, 2026
Culturing Microglia from the Neonatal and Adult Central Nervous System
Published on: August 9, 2013
Microglia colonize the developing brain by clonal expansion of highly proliferative progenitors, following allometric
Liam Barry-Carroll1, Philip Greulich2, Abigail R Marshall1
1School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK.
Abstract:
Microglia arise from the yolk sac and enter the brain during early embryogenesis. Upon entry, microglia undergo in situ proliferation and eventually colonize the entire brain by the third postnatal week in mice. However, the intricacies of their developmental expansion remain unclear. Here, we characterize the proliferative dynamics of microglia during embryonic and postnatal development using complementary fate-mapping techniques. We demonstrate that the developmental colonization of the brain is facilitated by clonal expansion of highly proliferative microglial progenitors that occupy spatial niches throughout the brain. Moreover, the spatial distribution of microglia switches from a clustered to a random pattern between embryonic and late postnatal development. Interestingly, the developmental increase in microglial numbers follows the proportional growth of the brain in an allometric manner until a mosaic distribution has been established. Overall, our findings offer insight into how the competition for space may drive microglial colonization by clonal expansion during development.
Insights
Microglia colonization of the brain is driven by the clonal expansion of progenitor cells. This process ensures microglia numbers scale with brain growth, establishing a random distribution.
Area of Science:
- Neuroscience
- Developmental Biology
- Immunology
Background:
- Microglia, the brain's resident immune cells, originate from the yolk sac and colonize the brain during early development.
- Their proliferation and colonization patterns throughout embryogenesis and early postnatal life are not fully understood.
Purpose of the Study:
- To investigate the proliferative dynamics and spatial distribution of microglia during embryonic and postnatal brain development.
- To elucidate the mechanisms driving microglial colonization and expansion in the developing brain.
Main Methods:
- Utilized complementary fate-mapping techniques to track microglial development.
- Analyzed microglial proliferation, spatial distribution, and number changes in relation to brain growth.
Main Results:
- Demonstrated that microglial colonization is facilitated by clonal expansion of progenitor cells residing in specific brain niches.
- Observed a switch in microglial distribution from clustered to random patterns between embryonic and late postnatal stages.
- Found that microglial population expansion scales allometrically with brain growth until a mosaic distribution is achieved.
Conclusions:
- Microglial colonization is driven by the spatial expansion of progenitor clones, influenced by niche availability.
- The developmental increase in microglia numbers is proportionally linked to brain growth.
- Competition for space likely plays a role in driving microglial colonization through clonal expansion.
