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Updated: Jul 30, 2026
Isolation and Culture of Rodent Microglia to Promote a Dynamic Ramified Morphology in Serum-free Medium
Published on: March 9, 2018
Human and mouse microglia express connexin36, and functional gap junctions are formed between rodent microglia and
K Dobrenis1, H-Y Chang, M H Pina-Benabou
1Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA. dobrenis@aecom.yu.edu
Abstract:
Microglia, the tissue macrophages of the central nervous system (CNS), intimately interact with neurons physically and through soluble factors that can affect microglial activation state and neuronal survival and physiology. We report here a new mechanism of interaction between these cells, provided by the formation of gap junctions composed of connexin (Cx) 36. Among eight Cxs tested, expression of Cx36 mRNA and protein was found in microglial cultures prepared from human and mouse, and Cx45 mRNA was found in mouse microglial cultures. Electrophysiological measurements found coupling between one-third of human or mouse microglial pairs that averaged below 30 pico-Siemens and displayed electrical properties consistent with Cx36 gap junctions. Importantly, similar frequency of low-strength electrical coupling was also obtained between microglia and neurons in cocultures prepared from neocortical or hippocampal rodent tissue. Lucifer yellow dye coupling between neurons and microglia was observed in 4% of pairs tested, consistent with the low strength and incidence of electrical coupling. Cx36 expression level and/or the degree of coupling between microglia did not significantly change in the presence of activating agents, including lipopolysaccharide, granulocyte-macrophage colony-stimulating factor, interferon-gamma, and tumor necrosis factor-alpha, except for some reduction of Cx36 protein when exposed to the latter two agents. Our findings that intercellular coupling occurs between neuronal and microglial populations through Cx36 gap junctions have potentially important implications for normal neural physiology and microglial responses in neuronopathology in the mammalian CNS.
Insights
Microglia and neurons communicate via connexin 36 (Cx36) gap junctions, a novel interaction mechanism. This intercellular coupling impacts central nervous system (CNS) physiology and neuronopathology.
Area of Science:
- Neuroscience
- Cell Biology
- Neuroimmunology
Background:
- Microglia, the brain's immune cells, interact with neurons.
- These interactions influence neuronal survival and function.
- A new communication pathway between microglia and neurons is explored.
Purpose of the Study:
- To identify novel mechanisms of microglial-neuronal interaction.
- To investigate the role of connexins (Cxs) in mediating this communication.
- To characterize the properties of gap junctions between microglia and neurons.
Main Methods:
- Cultured human and mouse microglia and neuron-microglia co-cultures.
- Connexin (Cx) mRNA and protein expression analysis.
- Electrophysiological recordings and Lucifer yellow dye coupling assays.
Main Results:
- Connexin 36 (Cx36) mRNA and protein were detected in microglia.
- Electrical coupling (1/3 of microglial pairs) and dye coupling (4% of pairs) were observed between microglia and neurons.
- Coupling strength was low and not significantly altered by common activating agents, except for a reduction in Cx36 protein by interferon-gamma and tumor necrosis factor-alpha.
Conclusions:
- Cx36 forms functional gap junctions between microglia and neurons in the CNS.
- This intercellular coupling represents a new mechanism of cell-cell communication.
- Cx36-mediated coupling has significant implications for neural physiology and diseases involving neuroinflammation.
