Modeling Repetitive Concussive Head Injuries in a Mouse Model

Begin by attaching the impact tip and probe tip to an impact device.

Next, secure an anesthetized mouse in a stereotaxic frame.

Position the impact tip between the interfrontal and lambdoid sutures, vertically aligned with an imaginary horizontal line between the ears.

Zero the X and Y channels on the stereotaxic control panel to prevent impact center shift when switching the tips.

Manually move the probe tip to the impact center and lower it to touch the impact site. Clip a contact sensor to the mouse's tail.

Zero the Z channel, then reposition the impact tip until X and Y are zero and Z reads minus four.

Apply the impact at a specific velocity.

Measure apnea—the time from the impact to the mouse's first breath—to determine the injury severity.

Allow the mouse to recover.

Repeat the impact at specified intervals. Repeated impacts rupture blood vessels in the brain, causing microbleeds and triggering astrocyte activation, mimicking a mild human-like concussion.