Fig. 8. Functional connectivity between subcortical nodes of the default ascending arousal network and cortical nodes of the default mode network and their relationship to structural connectivity.

(A) Boxplots of the DMN functional connectivity for each dAAN node. Y-axis represents the strength of functional connectivity (unitless) relative to the cortical DMN connectivity measured by the NASCAR method. VTA voxels showed the highest level of maximal functional connectivity with the DMN, while MnR had the highest level of median connectivity with the DMN. (B) Scatter plot between the mean of functional connectivity (x-axis) and the structural connectivity probability (y-axis) for each brainstem nucleus. (C) The counterpart grouped by the predominant type of neurotransmitter for each node: cholinergic = PTg and LDTg; dopaminergic = VTA; glutamatergic = PBC, mRt, and PnO; noradrenergic = LC; serotonergic = MnR and DR.