Conclusion
Infiltrated monocytes were successfully observed 1 day after noise exposure, preceding the increase in the macrophage population. This finding supports the proposal that infiltrated monocytes transform into macrophages.
Methods
In wild-type and CX3CR1+/GFP C57/B6 mice, inflammatory monocytes were identified by immunofluorescence of mouse cochlear cells. The findings were confirmed and quantitated by flow cytometry.
Results
One day after noise exposure, monocytes were identified in the spiral ligament. Flow cytometric analysis confirmed that the monocyte population peaked on post-noise exposure day 1 and decreased thereafter. On day 3 after noise exposure, amoeboid-type macrophages increased in the crista basilaris, and on day 5, they spread to the basilar membrane.