The first step in analyzing the neurons' damage thresholds is to perform a controlled deformation on the cells. Within this line of research, deformation has been achieved in two ways, the most recent of which is through use of the CAI (Cultured Axonal Injury) System. It introduces compressed air into an airtight chamber to deform the transparent membrane, thus stretching the cell.
Raman Spectroscopy allows us to analyze the neuron, the main structural and functional component of the brain, to help us understand its biochemical, electrical, and mechanical behaviors under different mechanical loadings. If we define the neuron injury level by these behaviors, we can determine its relationship to the loading level. With this information, we can identify upper and lower damage thresholds as a function of strain and strain rate - important parameters for the designing of helmet effective at preventing bTBI.
The external mechanical load will firstly cause the mechanical deformation of neurons, and then, when this deformation reaches to a critical point (threshold), it will initiate the chemical/biological response. The chemical/biological response can cause the neuronal function loss—neuronal injury. This process is considered to be the mechanism of the mild traumatic brain injury (mTBI) at the cellular level. Understanding the relationship between the neuronal mechanical response and their biological responses is the first important step to understand the mechanism of mTBI.