Mild traumatic brain injury in the rat alters neuronal number in the limbic system and increases conditioned fear and anxiety-like behaviors

► Mild TBI in the rat increases apoptosis and decreases neurons in the hippocampus. ► Mild TBI decreases apoptosis and increases neuronal number in the amygdala. ► Mild TBI increases fear and anxiety without affecting motoric function. ► Alterations to the limbic system may underlie fear and anxiety following mild TBI.