To investigate the relationship between chronic sensory processing abnormalities and cognitive impairment following repeated concussions in a mouse model.
Approach:
Experimental Model: Used a repeated closed-head injury (rCHI-5x) mouse model targeting the frontal cortex to assess sensory dysfunction and cognitive performance.
Behavioral Testing: Conducted multisensory behavioral tasks and cognitive tasks with and without sensory distractors at 3 months post-injury.
Key Findings:
rCHI mice exhibited significant sensory dysfunction across multiple modalities, including increased tactile sensitivity, tactile avoidance, and impaired habituation to auditory startle, despite the absence of gross structural brain damage and preserved learning and memory under low-demand conditions.
Cognitive deficits in rCHI mice emerged only when auditory and tactile sensory distractors were introduced during testing, unmasking impairments that were not evident under baseline conditions.
Strong associations were found between the severity of sensory hypersensitivity, impaired sensory habituation, and deficits in cognitive flexibility in rCHI mice, but not in sham controls.
Interpretation:
Chronic sensory dysregulation following repeat mild concussion may contribute to cognitive impairment under conditions of increased sensory load.
Limitations:
The study was conducted in a mouse model, which may not fully replicate human conditions.
The long-term effects of sensory dysregulation on cognitive function beyond the study period were not assessed.
Conclusion:
Persistent sensory processing and gating dysfunction may be associated with cognitive deficits related to post-concussion syndrome.
