Predicting changes in cortical electrophysiological function after in vitro traumatic brain injury.

Area of Science:

• Neuroscience
• Biomechanical Engineering
• Computational Biology

Background:

• Finite element (FE) models predict brain deformation in traumatic brain injury (TBI).
• Current FE models lack criteria to link mechanical stimuli to biological consequences.
• Predicting functional responses requires understanding tolerance limits of neural tissue.

Purpose of the Study:

• To develop functional tolerance criteria for the cortex relating mechanical stimuli to electrophysiological function.
• To quantify alterations in neuronal network activity post-TBI using controlled mechanical deformation.
• To provide data for enhancing FE models' predictive accuracy for TBI outcomes.

Main Methods:

• Organotypic cortical slice cultures subjected to equibiaxial stretch simulating TBI mechanical forces.
• Electrophysiological function assessed using microelectrode arrays 4-6 days post-injury.
• Nonlinear regression analysis to correlate mechanical parameters (strain, strain rate) with electrophysiological outputs.

Main Results:

• Electrophysiological changes were complexly dependent on strain and strain rate.
• The cortex exhibited less spontaneous activity and excitability compared to the hippocampus.
• Cortical tissue showed reduced susceptibility to significant electrophysiological changes from mechanical deformation.

Conclusions:

• Functional tolerance criteria were established for cortical electrophysiological responses to mechanical injury.
• The cortex is relatively resilient to deformation-induced functional deficits compared to other brain regions.
• Incorporating these findings into FE models can improve TBI consequence prediction.