Neural markers of vulnerability to anxiety outcomes following traumatic brain injury

Abstract

Anxiety outcomes following traumatic brain injury (TBI) are complex, and the underlying neural mechanisms are poorly understood. Here, we developed a multidimensional behavioral profiling approach to investigate anxiety-like outcomes in mice that takes into account individual variability. Departing from the tradition of comparing outcomes in TBI versus sham groups, we identified animals within the TBI group that are vulnerable to anxiety dysfunction by applying dimensionality reduction, clustering and post-hoc validation to behavioral data obtained from multiple assays for anxiety at several post-injury timepoints. These vulnerable animals expressed distinct molecular profiles in the corticolimbic network, with downregulation in GABA and glutamate, and upregulation in NPY markers. Indeed, among vulnerable animals, not resilient or sham controls, severity of anxiety outcomes correlated strongly with expression of molecular markers. Our results establish a foundational approach, with predictive power, for reliably identifying maladaptive anxiety outcomes following TBI and uncovering neural signatures of vulnerability to anxiety.