Figure 7

Relationship between behavioral scores in the light–dark box (LDB) test and the splash test (ST), and microglial-related neuroinflammation in the studied brain regions. From the overall results, the principal component analyses (PCAs) revealed that four principal components (PC1-4) explain 75% of the variance of the data sets (hypothalamic, a; cortical, d; and subcortical regions, g). Heat-maps of the loading values of PC1-4 show that microglial density and IBA-1 relative expression strongly correlate with PC1 for the three data sets (b, e, h), and that behavioral scores mostly correlate with PC2 in hypothalamic (b) and cortical regions (e). Only the time spent in the lit compartment during the LDB test correlates with PC2 at subcortical level (h). Biplots for each data set show IBA-1 relative expression predicts microglial density, and that ST and LDB behavioral scores are slightly predicted by the magnitude of microgliosis (c, f, i). Biplots illustrate two clusters of individuals that assemble in terms of microglial-related neuroinflammation. Thus, the pathological experimental group (HFD-VEH) shapes one of the clusters (c, f, i, red dots), and the second cluster comprises non-obese or obese animals where neuroinflammation had been rescued (c, f, i; respectively: STD-VEH, grey dots; STD-LA, bleu dots; HFD-LA, green dots). Entries in the lit compartment –LIT entries; time spent in the lit compartment, –LIT time; time in the transition zone, –TZ time; latency to first grooming event, –ST latency; total time grooming, –ST total.