The role of microglia and their CX3CR1 signaling in adult neurogenesis in the olfactory bulb.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29251592.
- Also identified by DOI 10.7554/eLife.30809 and PMC identifier 5734876.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Microglia play important roles in perinatal neuro- and synapto-genesis. To test the role of microglia in these processes during adulthood, we examined the effects of microglia depletion, via treatment of mice with the CSF-1 receptor antagonist PLX5622, and abrogated neuronal-microglial communication in CX3C receptor-1 deficient (<i>Cx3cr1<sup>-/-</sup></i>) mice. Microglia depletion significantly lowered spine density in young (developing) but not mature adult-born-granule-cells (abGCs) in the olfactory bulb. Two-photon time-lapse imaging indicated that microglia depletion reduced spine formation and elimination. Functionally, odor-evoked responses of mitral cells, which are normally inhibited by abGCs, were increased in microglia-depleted mice. In <i>Cx3cr1<sup>-/-</sup></i> mice, abGCs exhibited reduced spine density, dynamics and size, concomitantly with reduced contacts between <i>Cx3cr1</i>-deficient microglia and abGCs' dendritic shafts, along with increased proportion of microglia-contacted spines. Thus, during adult neurogenesis, microglia regulate the elimination (pruning), formation, and maintenance of synapses on newborn neurons, contributing to the functional integrity of the olfactory bulb circuitry.
Medical subject headings
- CX3C Chemokine Receptor 1
- Cell Differentiation
- Microglia
- Neurogenesis
- Olfactory Bulb
- Signal Transduction