Fig. 3

Effect of chronic simvastatin treatments on hippocampal cholesterol level. a Schematic diagram of paDESI-MS imaging setup. HV, high voltage; N₂, nitrogen; MS: mass spectrometry. b Representative brain cholesterol image and MS spectra of cholesterol obtained from the brain slice. c Representative cholesterol images of brain slices from the vehicle- and simvastatin-treated mice. Normalized brain cholesterol intensity in the vehicle- and simvastatin-treated mice. n = 7–9. Scale bar: 1 mm. Simv: simvastatin, Veh: vehicle. Data are represented as mean ± SEM. *P < 0.05 based on an unpaired t test. d Schematic diagram showing simvastatin treatments, NOR behavioral tests and paDESI-MS imaging in the same mice. Correlation analysis of the simvastatin-induced cholesterol reduction (% reduction vs control group) in the hippocampus of mice and their novel object preference (%) (n = 10). e Schematic diagram showing simvastatin treatments, MWM behavioral tests and paDESI-MS imaging. Correlation analysis of the extent of simvastatin-induced cholesterol reduction in hippocampus and the latency in finding the platform (n = 10). The latency data at the last day of MWM training was shown. All the dots corresponding to individual mice were randomly selected from the simvastatin-treated group. n = 10 mice