Figure 8. Systemic MB differentially modified the intrinsic connectivity of thalamic, medial temporal lobe, and motor loop networks.

Graph theory methods showed that azide (AZ) in the PCC induced an increase in the mean clustering index (γ) (i.e. how close are neighboring regions to be completely interconnected) in the thalamus, but no significant change in that of the medial temporal lobe (MTL) or the visuomotor loop (VML). In each one of the three networks, methylene blue (MB) induced significant γ changes not only compared to AZ but also to control. MB decreased the mean clustering index in thalamic and VML regions, but increased it in the MTL. This differential effect is consistent with the induction of a local activity-dependent adaptive reconfiguration by MB, as opposed to a general and non-specific metabolic-enhancing effect. * = significantly higher than control. + = significantly lower than control, p < .05.