Effects of escapable and inescapable stressors on behavior and interleukin-2 in the brain

This study aimed to clarify the effects of inescapable and escapable stressors on behavior and interleukin-2 (IL-2) levels in the brain. Inescapable trials, consisting of pairings of conditioned and unconditioned stimuli, were used to induce fear-conditioned stress, whereas trials of escapable pairings of conditioned and unconditioned stimuli in an active avoidance test were used as acute and conditioned stressors. IL-2 levels in the brain were analyzed by enzyme-linked immunoadsorbent assays. Inescapable and escapable stressors had different effects on behavior in the modified active avoidance test and on IL-2 levels in brain areas that are known to be involved in emotional processes. These data provide insight into the pathophysiological role of IL-2 in stress-related disorders.