Interestingly, the frontal and anterior cingulate cortices, which were enriched in our tissue-based analyses, as well as the hippocampus and the striatum, which were implicated in our cell type-based analyses, are among the regions that are consistently implicated in neuroimaging studies of OCD41,71–73. Enrichment in MSNs in the striatum is consistent with their role in the observed aberrant circuitry in OCD, where the D1 MSNs project to the globus pallidus interna and the substantia nigra in the direct pathway and the D2 type MSNs project to the globus pallidus externa in the indirect pathway74. However, MSNs are also enriched in major depressive disorder75, schizophrenia76 and intelligence77, suggesting that the observed enrichment is not specific for OCD.
