Fig. 4: Functional connectivity and graph analysis in DAT-KO, DAT-HET and WT rats.

A Network-based statistic (NBS) results demonstrate a pattern of strong cortical hyperconnectivity and midbrain hypoconnectivity in DAT-KO compared to WT rats. Significantly stronger connections in DAT-KO rats are illustrated in red (stringent threshold p_pt < 0.01, p_NBS < 0.05) and orange (lenient threshold p_pt < 0.05, p_NBS < 0.05), while significantly weaker connections in the DAT-KO group are illustrated in blue (lenient threshold p_pt < 0.05, p_NBS < 0.05). B Normalized local clustering coefficients on the whole-brain network show a pattern of significant increase in frontal regions and a decrease in midbrain dopaminergic regions and parts of the thalamus in DAT-KO compared to WT rats. C Small-world propensity decreased across genotypes from WT to DAT-HET and DAT-KO animals. D Small-world propensity negatively correlated with total distance moved and was positively associated with relative dorsal striatal volume in DAT-KO rats. E Both global and local efficiencies demonstrated a robust decrease in DAT-KO animals. F Robustness against targeted and random failures showed a prominent reduction in DAT-KO rats. Glob. Eff. global efficiency, Mean Loc. Eff. mean local efficiency, Rob. (targ.) robustness against targeted attacks; Rob. (rand.) robustness against random attacks; Small-World Prop. small-world propensity; TBV total brain volume. ^#p < 0.10; *p < 0.05; **p < 0.01; ***p < 0.001. All illustrated metrics are corrected for differences in isoflurane levels (for details, see Supplement). For brain regions abbreviations see Fig. 3.