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Updated: May 5, 2026
Culturing Microglia from the Neonatal and Adult Central Nervous System
Published on: August 9, 2013
Activity-dependent regulation of microglia numbers by pyramidal cells during development shape cortical functions
Sanjana Kumaraguru1, James Morgan1, Fong Kuan Wong1,2
1Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK.
Abstract:
Beyond their role as immune sentinels, microglia are actively involved in establishing and maintaining cortical circuits. Alteration in microglial numbers has been associated with abnormal behaviors akin to those observed in neurodevelopmental disorders. Consequently, establishing the appropriate microglial numbers during development is crucial for ensuring normal cortical function. Here, we uncovered a dynamic relationship between pyramidal cells and microglia that tunes microglial numbers and development through distinct phases of mouse postnatal development. Changes in pyramidal cell activity during development induce differential release of activity-dependent proteins such as Activin A, which, in turn, adjusts microglial numbers accordingly. Decoupling of this relationship not only changes microglial numbers but has a long-term consequence on their role as synaptic organizers, which ultimately affects cortical function. Our findings reveal that microglia adapt their numbers to changes in pyramidal cell activity during a critical time window in development, consequently adjusting their numbers and function to the demands of the developing local circuits.
Insights
Microglia numbers are dynamically regulated by pyramidal cell activity during development. This crucial relationship ensures proper cortical circuit formation and function, impacting neurodevelopmental outcomes.
Area of Science:
- Neuroscience
- Developmental Biology
- Immunology
Background:
- Microglia, the brain's resident immune cells, play a vital role beyond immune surveillance, actively participating in the development and maintenance of cortical circuits.
- Aberrations in microglial populations are linked to behavioral abnormalities characteristic of neurodevelopmental disorders, highlighting the importance of precise microglial numbers during development.
- Establishing appropriate microglial numbers is critical for normal cortical function and neurodevelopment.
Purpose of the Study:
- To investigate the dynamic relationship between pyramidal cells and microglia during postnatal development.
- To elucidate the mechanisms by which pyramidal cell activity influences microglial numbers and function.
- To understand the long-term consequences of disrupting this communication on cortical circuit organization and function.
Main Methods:
- Utilized mouse models to study postnatal development of cortical circuits.
- Monitored changes in pyramidal cell activity and their impact on microglial populations.
- Investigated the role of activity-dependent proteins, such as Activin A, in regulating microglial numbers.
- Assessed the functional consequences of altered microglial numbers on synaptic organization and cortical function.
Main Results:
- A dynamic interplay between pyramidal cells and microglia was identified, regulating microglial numbers across distinct developmental phases.
- Pyramidal cell activity modulates the release of proteins like Activin A, which in turn adjusts microglial cell density.
- Disruption of the pyramidal cell-microglia communication led to altered microglial numbers and impaired synaptic organization.
- Microglial adaptation to pyramidal cell activity during a critical developmental window is essential for circuit maturation.
Conclusions:
- Microglial numbers are precisely tuned by pyramidal cell activity during a critical developmental period.
- This activity-dependent regulation is crucial for establishing appropriate microglial populations for developing cortical circuits.
- The findings reveal a novel mechanism linking neuronal activity to microglial development and function, with implications for neurodevelopmental disorders.
