GFAP and major depressive disorder: Using the same model we also found significant behavioral and physiological changes after repeated mild blast exposure, including increased anxiety- and depression-related behaviors, elevated heart rate (up to 24 h post-injury), and increases in injury-related blood-based biomarkers (e.g., glial fibrillary acidic protein, neuron-specific enolase, and neurofilament) (44, 45).