MIR941-1 and viral infectious disease: Despite the fact that the AAV1 virus can be retrogradely transported via axons to the contralateral region [30] and the cerebellum [31], this system allowed us to restrict viral infection to the target site and to discrete regions of the mouse brain while then specifically monitoring potential transport of virally expressed pre-MIR941-1 outside of the brain using gene-specific PCR.