Sevoflurane exaggerates cognitive decline in a rat model of chronic intermittent hypoxia by aggravating microglia-mediated neuroinflammation via downregulation of PPAR-γ in the hippocampus

•Chronic intermittent hypoxia (CIH) causes cognitive decline.•CIH triggers microglia-mediated neuroinflammation.•Sevoflurane exaggerates cognitive decline under CIH conditions.•Sevoflurane aggravates microglia-mediated neuroinflammation under CIH conditions.•Sevoflurane downregulates hippocampal PPAR-γ.