Initial Biphasic Fractional Anisotropy Response to Blast-Induced Mild Traumatic Brain Injury in a Mouse Model.

Abstract

INTRODUCTION: Blast-induced mild traumatic brain injury was generated in a mouse model using a shock tube to investigate recovery and axonal injury from single blast. METHODS: A supersonic helium wave hit the head of anesthetized male young adult mice with a reflected pressure of 69 psi for 0.2 ms on Day 1. Subsequently, the mice were cardioperfused on Days 2, 5, or 12. The isolated brains were subjected to diffusion tensor imaging. Reduced fractional anisotropy (FA) indicated axonal injury. RESULTS: After single blast, FA showed a biphasic response in the corpus callosum with decrease on Days 2 and 12 and increase on Day 5. CONCLUSIONS: Blast-induced mild traumatic brain injury in a mouse model follows a biphasic FA response within 12 days after a single blast similar to that reported for human subjects.