Figure 4

Model of how microRNA regulation of prosurvival target genes could result in differential suppression and differential cell survival after TBI. miR-15b-mediated suppression of random fluctuations in expression levels of pro-survival target genes, such as Bdnf, could lower the threshold for cell survival and result in neurodegeneration after TBI. Inset shows expression levels (from separate microarray experiments) of miR-15b in hippocampus of traumatic brain injured (TBI) rats and expression levels of Bdnf in pools of laser capture microdissected dying and surviving hippocampal pyramidal neurons after TBI.