Accurately Modeling Mild Traumatic Brain Injury to Better Understand Function Mechanisms

Mild traumatic brain injuries (mTBIs) are a prevalent health issue in North America. There is increasing pressure to utilize ecologically valid models of closed-head mTBI in the preclinical setting to increase translatability to the clinical population. The awake closed-head injury (ACHI) model described here produces clinically relevant behavioral deficits in rodents without the need for a craniotomy or the use of an anesthetic. The technique involves rapidly accelerating the animals head, rather than striking it, so it does not normally induce fatalities, skull fractures, or brain bleeds, and is more consistent with being a mild injury. Indeed, the mild nature of the ACHI procedure makes it ideal for studies investigating repetitive mTBI (r-mTBI). Our recent work indicates that the ACHI is associated with a distributed brain injury that results in microbleeds, microglia activation and synaptic pruning. This in turn results in changes in synaptic plasticity, the main biological model for learning and memory processes. Future studies will continue to explore deficits in synaptic plasticity, as well as how an aged brain is affected by incurring an mTBI early in life.

Learning Objectives:

1. Discuss the merits and pitfalls of The Awake Closed Head Injury (ACHI) model for brain injury research. 

2. Describe how mild traumatic brain injury can affect the structure and function of the brain.  

3. Discuss opportunities for future studies using a clinically relevant model of mild traumatic brain injury like the ACHI.