722 - Impaired socioemotional and coping skills after TBI: An experimental investigation in rats

Traumatic brain injury (TBI) leads to persistent deficits in social and emotional functioning that impair rehabilitation and quality of life. Mechanisms of disrupted social preference and recognition remain poorly understood. We aimed to establish and validate a preclinical model of post-TBI socioemotional dysfunction with emphasis on social-enhanced safety learning under stress (Social Familiarity-induced Anxiolysis, SoFiA). We hypothesized controlled cortical impact (CCI) in the right frontal or parietal cortex would impair safety learning, coping capacity, and social preference behaviors in a locus-specific manner. We further hypothesized pre-injury social familiarity may provide post-injury protection against deficits in these domains.

Design:

Adult male Sprague-Dawley rats were randomized to moderate right frontal CCI, moderate right parietal CCI, or sham groups (n=12-14). After 14-day recovery, cohorts underwent social interaction-habituation (SI-hab), social recognition (SR), and shock probe defensive burying (SPDB) testing under stressful (bright) or non-stressful (dim) lighting conditions. SI-hab and SR tasks assessed safety learning and social preferences with familiar vs. novel partners, while SPDB assessed passive and active coping capacities. Separate cohorts received pre-injury SI-hab training intervention.

Results:

Both CCI groups displayed impaired SoFiA acquisition with persistently reduced SI times despite social familiarity (p< 0.05), alongside diminished preference for novel partners during stress-dependent SR (p< 0.05), consistent with anxiety-like behavior and aberrant preferences. Both injury groups also showed reduced active coping in SPDB (less burying, p< 0.05). Preliminary findings indicate pre-injury SI-hab training partially preserved post-injury SI performance with established partners, but not novel partners.

Conclusions:

Right frontal and parietal CCI induced persistent, locus-specific socioemotional dysfunction in rats. The SoFiA paradigm provides a translational framework to measure post-TBI socioemotional mechanisms and test interventions. Early socialization and familiarity may confer socioemotional protection and enhance recovery post-TBI. These findings highlight a novel paradigm for the development of rehabilitation interventions that mitigate socioemotional dysfunction after TBI.