Fig. 3
Co-expression network analyses on brain aging. a Three co-expression modules in the aging hippocampus were highly correlated with age in gene expression (positive correlation for genes associated with immune and demyelination; negative correlation for those with synaptic transmission). Each bar graph corresponds to an eigengene (representative expression of each module, left panel). b Linear regressions between intramodular connectivity and gene significance (the extent of correlation with aging). c The observed number of physically connected genes (in the interactome) in each co-expressed module was compared with that of randomly generated modules. From top to bottom, yellow, red, and brown modules were displayed. Yellow module was enriched in immune process, red in myelination and brown in synaptic transmission
