Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv 64239, Israel.
Cereb Cortex. 2013 Jan;23(1):28-35. doi: 10.1093/cercor/bhr369. Epub 2012 Jan 30.
Trauma-related psychopathology has been associated with an intense emotional reaction to stressful event. Emotional responses have evolved to signal the presence of risks to be avoided or of rewards to be approached in the environment. Thus, individuals' sensitivity to signals of risk and reward may affect the level of stress vulnerability. Stress, however, can modify these sensitivities as well. In the current functional magnetic resonance imaging (fMRI) study, we prospectively probed the neural correlates of such sensitivities in 24 healthy soldiers by using an interactive game that encompasses risky and rewarding intervals both pre-exposure and post-exposure to stressful military service. As expected, risky and rewarding intervals elicited selective responses in the amygdala and nucleus accumbens (Nacc), respectively. Furthermore, increased post-traumatic stress disorder symptoms post-exposure (i.e., stress vulnerability) corresponded to greater amygdala's response to risk both pre-exposure and post-exposure and to decreased NAcc response to reward only post-exposure. By combining these regional responsivities post-exposure, we accurately identified all the most vulnerable soldiers. Imbalanced neural responsivity to risk and reward following exposure to stress may therefore constitute a marker for stress vulnerability. Such identification of vulnerability biomarkers can aid future diagnostic and therapeutic efforts by allowing early detection of vulnerability as well as follow up on patient's treatment progression.
创伤相关精神病理学与对压力事件的强烈情绪反应有关。情绪反应是为了在环境中发出危险信号，以避免或接近奖励。因此，个体对风险和奖励信号的敏感性可能会影响压力易感性的程度。然而，压力也可以改变这些敏感性。在当前的功能磁共振成像（fMRI）研究中，我们通过使用一个互动游戏来前瞻性地探测 24 名健康士兵的这种敏感性的神经相关性，该游戏涵盖了有压力的军事服务之前和之后的风险和奖励间隔。正如预期的那样，风险和奖励间隔分别引起杏仁核和伏隔核（Nacc）的选择性反应。此外，暴露后创伤后应激障碍症状增加（即压力易感性）与暴露前和暴露后对风险的杏仁核反应增加以及仅暴露后对奖励的 NAcc 反应减少有关。通过结合这些区域的反应性，我们准确地识别出了所有最脆弱的士兵。暴露于压力后对风险和奖励的不平衡神经反应可能构成压力易感性的标志物。这种脆弱性生物标志物的识别可以通过早期检测脆弱性以及跟踪患者的治疗进展，为未来的诊断和治疗努力提供帮助。
