Everyone either knows someone or heard of someone that has gotten a concussion. A concussion is a form of traumatic brain injury. The Center for Disease Control (CDC) estimates that over 1 million people a year experience a concussion. Concussions can also lead to cognitive and motor impairments.
Currently, there are no effective treatments for concussions. People typically heal over time. Doctors treat the symptoms (e.g.. headaches, concentration problems, trouble sleeping, memory), but do not tackle the actual problem (i.e., how the injury affects certain functions of the brain). This is due to the inability to see what is happening to the brain as it receives a concussion. Because of that, researchers use animal models (e.g., lab rats, mice, etc.) to assess how the brain is affected by concussions.
Animal models are used to simulate almost every form of human brain injury. Animal models of concussion are important to help understand how the brain responds to injury. There are many different models of producing a concussion for animals, some of which model how the concussion can happen with people. Researchers from Wayne State University published an article explaining the pros and cons of some of the injury models currently being used today (Angoa-Perez et al., 2014, J. Neurochemistry).
One point the article mentions is how conducting concussion research can be tricky when there are multiple ways to give an animal a concussion. One of the most common injury models is the weight drop model (WDM). It works, well, exactly how it sounds. The weight can be modified to produce either a mild, moderate or severe concussion. Although it sounds terrible, it is nowhere as severe as when Wile E Coyote gets hit by an anvil on a Looney Toons episode.
Most concussion research is conducted with rodents (rats and mice) as the animal model. This is due to the fact that rodent brains are structurally similar to human brains. Laboratory animal research facilities have multiple veterinarians and animal care specialists on staff to make sure the animals are in good hands and are treated humanely. Since we can’t talk to animals, we rely on behavior models to see how much the animal’s brain is affected by the concussion. Researchers develop tasks that relate to the symptoms shown in humans. It’s too bad Dr. Doolittle isn’t around to ask the animals how they are feeling.
Not only are researchers studying the effect of concussion on the brain but also how multiple head injuries can affect recovery and the overall health of a person. In recent years, the models of concussion are advancing. Previous models implemented restraints to hold animals in place while a piece of their brain would be exposed during the impact. The problem with that is the impact(s) may cause more damage to the brain than it would when under more normal circumstances. Some of the injuries due to brain exposure can include bleeding, obvious bruising, and skull fractures. The presence of any one of those additional injuries may mean a more severe concussion. Newer models have animals free of restraints with their skulls intact. These models allow the animals to move after the impact of the injury device (like how humans move after getting a concussion).
The newer injury models have recently been implemented in concussion research. As of right now, researchers are still conducting experiments using newer injury models to find out more information about concussions. Although we may not fully understand everything, these newer animal models of concussion bring us one step closer to understanding what is going on in the brain.
Edited by Benjamin Greulich and JiHae Koo