and morphine treated groups (Fig. S8A). Cell types were clustered across individual rhesus macaques, which yielded similar results to our previous non-human primate striatal findings34 (Fig. S8C). Consistent with our findings of elevated DNA damage markers in individuals with OUD, rhesus macaques administered morphine for nearly 6 months exhibited significant enrichment of DNA damage markers in striatal neurons (P = 0.05, linear regression; Fig. 3e). DNA damage marker enrichment was found across each of the major neuronal subtypes (P < 0.00066, linear regression; Fig. 3e). Despite limitations (i.e., species differences of striatal regions and species-specific opioid-induced gene expression changes) (Figs. S8, S9)83, elevated DNA damage markers were evident in striatal neurons from individuals with OUD and non-human primates chronically administered opioids.
