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Updated: Apr 30, 2026
In Vivo Chronic Two-Photon Imaging of Microglia in the Mouse Hippocampus
Published on: July 6, 2022
Surveillance, phagocytosis, and inflammation: how never-resting microglia influence adult hippocampal neurogenesis
Amanda Sierra1, Sol Beccari2, Irune Diaz-Aparicio2
1Ikerbasque Foundation, 48011 Bilbao, Spain ; Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, 48170 Zamudio, Spain ; Department of Neurosciences, University of the Basque Country, 48940 Leioa, Spain.
Abstract:
Microglia cells are the major orchestrator of the brain inflammatory response. As such, they are traditionally studied in various contexts of trauma, injury, and disease, where they are well-known for regulating a wide range of physiological processes by their release of proinflammatory cytokines, reactive oxygen species, and trophic factors, among other crucial mediators. In the last few years, however, this classical view of microglia was challenged by a series of discoveries showing their active and positive contribution to normal brain functions. In light of these discoveries, surveillant microglia are now emerging as an important effector of cellular plasticity in the healthy brain, alongside astrocytes and other types of inflammatory cells. Here, we will review the roles of microglia in adult hippocampal neurogenesis and their regulation by inflammation during chronic stress, aging, and neurodegenerative diseases, with a particular emphasis on their underlying molecular mechanisms and their functional consequences for learning and memory.
Insights
Microglia cells, traditionally linked to brain inflammation, also play a positive role in healthy brain functions. This review explores their impact on neurogenesis, learning, and memory, especially during stress and aging.
Area of Science:
- Neuroscience
- Immunology
- Cellular Biology
Background:
- Microglia are key regulators of brain inflammation, traditionally studied in disease contexts.
- Recent findings highlight microglia's crucial roles in normal brain function and cellular plasticity.
- Surveillant microglia are increasingly recognized as effectors in the healthy brain.
Purpose of the Study:
- To review the multifaceted roles of microglia in adult hippocampal neurogenesis.
- To examine how inflammation affects microglia during chronic stress, aging, and neurodegenerative diseases.
- To emphasize the molecular mechanisms and functional consequences of microglial activity on learning and memory.
Main Methods:
- Literature review of studies on microglia, neurogenesis, and inflammation.
- Analysis of molecular mechanisms underlying microglial regulation.
- Synthesis of findings on functional outcomes for cognition.
Main Results:
- Microglia contribute to adult hippocampal neurogenesis.
- Inflammation significantly modulates microglial functions in aging and disease.
- Microglial activity impacts learning and memory through various molecular pathways.
Conclusions:
- Microglia are essential for maintaining brain health and plasticity, not just in disease.
- Understanding microglial regulation by inflammation is critical for cognitive function.
- Targeting microglial pathways may offer therapeutic strategies for cognitive decline.
