We find our observation of selective dysregulation of miR-34a in the cerebellum consistent with growing evidence from the work of others and us demonstrating the selective dysregulation of genes implicated in BD etiology specifically in the cerebellum, namely ANK3 and CACNA1C, that have recently been reported43, 44 (S.J.H., manuscript in preparation). While the PFC remains a brain region commonly implicated in BD pathophysiology, the potential importance of the cerebellum in BD and other affective disorders is increasingly apparent with recent neuroimaging studies having revealed complex connectivity with the cerebral cortex45, 46, 51, 52, 72. Given the well-known topographical organization of the cerebellum into specialized regions, including those critical to affective processing72, future work in cerebellar subregions could help determine if miR-34a expression is dysregulated in areas implicated in control of emotional and affective behavior, and if these expression differences correlate with the selective dysregulated expression of ANK3 and CACNA1C that has also been observed in the postmortem cerebellum samples43, 44.
