Functional reorganization after traumatic brain injury: A group ICA-based resting-state fMRI study in a porcine model

Traumatic brain injury (TBI) is a serious health concern in the United States and worldwide. Understanding the mechanisms underlying resting-state functional activity can play an important role in profiling induced disruptions, potentially enabling accurate and timely interventions. Due to its homology to the human brain, the porcine brain is a valuable translational model for investigating focal TBI. In this study, we used the porcine controlled cortical impact TBI model targeting the motor cortex to evaluate dynamic disruptions in functional activity in mild or severe TBI, including hemispheric imbalance, reorganization, and compensation mechanisms, using independent component analysis (ICA). Our whole-brain findings revealed that immediately after TBI, high-level resting-state networks (RSNs), including the executive control (ECN) and cerebellar (CN), showed significantly decreased activity, whereas the sensory motor (SMN) network displayed preserved functional activity. Further hemispheric findings demonstrated a significant decrease in ipsilateral functional activity, whereas contralateral functional activity increased in SMN. Additionally, cortical areas (CoAs) associated with the SMN demonstrated a pronounced hemispheric imbalance at the acute phase. Hemispheric and CoAs analyses revealed a restoration of functional activity over a two-month period. These alterations and lateral imbalance suggest potential lateral reorganization, compensation mechanisms, and temporal recovery processes. These findings are consistent with outcomes previously demonstrated in human TBI patients, further underscoring the importance of the porcine translational model for investigating changes in brain activity or connectivity due to TBI and future novel treatments.