Measurement of viscoelastic properties of injured mouse brain after controlled cortical impact

Mechanical properties of brain tissue can provide vital information for understanding the mechanism of traumatic brain injury (TBI). As mouse models were commonly adopted for TBI studies, a method to produce injury to the brain and characterize the injured tissue is desired. In this paper, a complete workflow of TBI induction, sample preparation, and biomechanical characterization is presented for measurement of the injured brain tissue. A controlled cortical impact device was used to induce injury to the brain. By setting the angle, speed, and position of the impact, the level of brain injuries could be controlled. Viscoelastic properties of both injured and non-injured brain tissues were measured using a ramp-hold indentation test. Regions of interests (ROIs) were tested and compared to contralateral corresponding counterparts. Methods introduced in this paper could be easily extended to produce and test a variety of other injured soft biological tissues.