A brain region implicated in OUD, along with other psychiatric and neurological disorders, is the striatum. In the human brain, the striatum is anatomically divided into dorsal and ventral portions, with both the caudate and putamen recognized as subregions of the dorsal striatum. Functional changes in the caudate and putamen are involved in altered reward processing, habitual drug-seeking and relapse, along with the development of negative affect during opioid withdrawal24–27, underlying the key roles of the dorsal striatum in OUD. However, only a few studies have examined specific cell types in human dorsal striatum28, and to date, no study has resolved the cell type-specific molecular alterations in human striatum in OUD.
