What Headbutting Between Male Bighorns Reveals About Traumatic Brain Injury in Humans

WHEN LOOKING FOR solutions to traumatic brain injury (TBI) in football players, bighorn sheep are often used as an inspiration from the animal kingdom. The extreme headbutting between males is commonly believed to cause no brain trauma, as the sheep’s brain is thought to be protected by their namesake horns. Nicole Ackermans, PhD, sought to test this idea.

An ontogenetic series of bisected male, female, and juvenile bighorn sheep (Ovis canadensis) skulls, exposing the braincase. Credit: Nicole Ackermans, PhD, from the labs of Patrick Hof, PhD, and Joy Reidenberg, PhD

Dr. Ackermans investigated skull and brain anatomy of bighorn sheep and other headbutting animals to determine whether they do in fact avoid TBI. Her novel findings show that they do not escape this condition. Immunohistochemical markers of TBI revealed pathology similar to early-onset chronic traumatic encephalopathy in humans, with tau-positive structures grouped in the depths of the sulci in the prefrontal cortex.

This is the first instance of naturally-occurring TBI recorded in any bovid animal. Further study will provide insight on sheep as a model for TBI and advance our understanding of TBI recovery.

Dr. Ackermans is a postdoctoral fellow of the Swiss National Science Foundation, and divides her work between the Joy Reidenberg, PhD, Lab in anatomy and the Patrick Hof, PhD, Lab in neuroscience within Mount Sinai’s Friedman Brain Institute.