Fig. 6: Age-associated spatial diversity of sterol lipids in the mouse brain.

a Dissection of functional regions of the mouse brain (6 and 68 weeks old; n = 6 biologically independent samples for each group). Each sample was analyzed once by LC-IM-MS. b Numbers of significantly changed sterol lipids in brain regions between mice of two ages (two-sided Student’s t-test; p-value adjusted using FDR). c Dysregulated amplitudes of sterol lipids in the brain regions of young and old mice. The mean log₂ (fold-changes) values of dysregulated sterol lipids are marked in the plot. Red areas and green areas in the right panel represent mean increased and decreased amplitudes in the brain regions of young and old mice, respectively. d Concentrations and fold-changes of 24-hydroxycholesterol in the brain regions of young and old mice (n = 6 biologically independent samples for each group, two-sided Student’s t-test; p-value adjusted using FDR; p-value <0.05: *; p-value ≥0.05: NS). Box plots display median value (centerline), upper and lower quartiles (box limits), 1.5× interquartile range (bar), and points out of interquartile range are outliers. e Scatter plots showing two example pairs of sterol lipids with positive and negative correlations over ten brain regions. The p-value of the upper example pair is 0.00537 two-sided Student’s t-test, 95% confidence interval). The p-value of the lower example pair is 0.000721 (two-sided Student’s t-test, 95% confidence interval). The red lines indicate the linear fitting. The x-axes and y-axes are standardized as Z-scores of the mean log₂ (fold changes) values of sterols. f Network visualization of the sterol lipid correlations in ten brain regions between young and old mouse brains. The edges are correlations in the ten brain regions with R \(\ge\) 0.85 (Pearson correlation). The nodes are sterol lipids. The nodes of the network are color-coded based on the log₂ (fold changes) values of sterols in each brain region.