Fig 2: Respiratory complex levels and respiratory function are decreased in the Perioperative neurocognitive disorder (PND) mouse brain by downregulating both peroxisome proliferator-activated receptor-? coactivator-1a (PGC-1a) and Nuclear respiratory factor-1 (NRF-1) levels. (A,B) Protein levels of Atp5d and Atp5k (complex V); Cox5a (complex IV); and Ndufs6, Ndufb8, and Ndufb10 (complex I) were determined in hippocampal tissues collected from control and surgery mice (1 day post-surgery) (n = 4) (A) or from control and surgery mice (3 days post-surgery) (n = 5) (B), by immunoblotting and densiometric analysis. (C) Levels of PGC-1a and NRF-1 in the hippocampal tissues of control and surgery mice (1 day post-surgery) were determined by immunoblotting and densiometric analysis (n = 6). ß-actin was included as an input control. (D,E) Hippocampal tissues were isolated from control or surgery mice (1 day or 3 days post-surgery). Enzymatic activities of NADH dehydrogenase (complex I) (D) and cytochrome C oxidase (complex IV) (E) were assessed by an ELISA-based approach (n = 8 per group). (F–H) Hippocampal tissues were isolated from control or surgery mice (1 day or 3 days post-surgery) (n = 5 per group). (F) Adenosine triphosphate (ATP) levels were assessed by an ELISA-based analysis. (G) Mitochondrial membrane potential (MMP) levels were determined by the JC-1 fluorescence probe-based approach. (H) Relative reactive oxygen species (ROS) levels were determined by the DCFHDA probe-based approach. *P < 0.05; **P < 0.01; ***P < 0.001 by independent samples Student’s t-test; n.s. not significant; error bars denote the SEM.