It's yet another application of the square-cube law. As the animal scales smaller, the frontal area of the brain goes down per the second power, while the mass goes down per the third power.
When I finally got over laughing at your incredibly funny response, I got to thinking seriously - the volume, density etc of fluid in the skull is well known together with the physical characteristics of the cranium, brain, etc. It would at the very least be revealing from either real or digital modeling to see what mechanical shock if any the fluid provides.
Exactly. What is not clear to me is whether the chronic traumatic encephalopathy (CTE) from football, boxing etc, is just from the repeated blows to the head or if actual repeated/severe concussions are required. Is there a threshold of head trauma that will not cause CTE or is it all just a matter of degree such that we get a small amount of CTE even with minor blows to the head, and it just accumulates.
Our brains are too large and fragile and our fluid space is much thinner relative to our brains.