  Transcriptomics, regional cerebral blood flow (rCBF), and a spatial motor
virtual reality task were integrated using mediation analysis in a novel
demonstration of "imaging omics". Data collected in NCAA Division I football
athletes cleared for play before in-season training showed significant
relationships in a) elevated levels of miR-30d and miR-92a to elevated putamen
rCBF, (b) elevated putamen rCBF to compromised balance scores, and (c)
compromised balance scores to elevated miRNA levels. rCBF acted as a mediator
variable (minimum 70% mediation, significant Sobel's test) between abnormal
miRNA levels and compromised balance scores. Given the involvement of these
miRNAs in inflammation and immune function, and that vascular perfusion is a
component of the inflammatory response, these findings support a chronic
inflammatory model of repetitive head acceleration events (HAEs). rCBF, a
systems biology measure, was necessary for miRNA to affect behavior. These
results suggest miRNA as a potential diagnostic biomarker for repetitive HAEs.
