Analysis of isomiR types after traumatic brain injury (TBI). Analysis of cortical differentially expressed miRNAs revealed an increase, especially in 3′ end modifications (A,B). The miR-211 isomiR 5′–TTCCCTTTGTCATCCTTTGCCTT was significantly increased after TBI (B, p < 0.05). For miR-146a, (C) several isomiRs were detected. These 2 isomiRs showed increased modifications at the 3′ end (5′– TGAGAACTGAATTCCATGGGT- and 5′– TGAGAACTGAATTCCATGGGTTT; p < 0.05). Quantitative RT-PCR chemistry detecting all 3′ end isomiRs (D) (FC = 1.7, p < 0.05) revealed a difference between controls and post-TBI animals. Primer assay targeting only canonical miR-146a did not detect this increase (see Supplementary Figure S3, FC = 1.4, p > 0.05). Interestingly, RNA folding assessment predicted the linear miR-146a form to change to a hairpin-like structure when insertions were detected in the miRNA 3′ end (E). Statistical significance: *, p < 0.05; **, p < 0.01.