Waddell Jaylyn, Bangasser Debra A, Shors Tracey J
Department of Psychology and Center for Collaborative Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA.
J Neurosci. 2008 May 14;28(20):5290-4. doi: 10.1523/JNEUROSCI.1129-08.2008.
The basolateral nucleus of the amygdala (BLA) has been implicated in the modulation of learning after stress. Acute inescapable stress enhances classical eyeblink conditioning in male rats, whereas the same stressor impairs eyeblink conditioning in female rats. The experiments here directly assessed whether inactivation of the BLA during stress exposure would block both the stress-induced facilitation in males and the retardation of eyeblink conditioning in females. To this end, the BLA was temporarily inactivated by infusion of the GABA agonist muscimol before acute stressor exposure. All rats were trained in a different context 24 h later. Males infused with muscimol before the stressful event did not exhibit facilitated eyeblink conditioning, whereas those infused with the vehicle emitted more conditioned responses than unstressed males. Females infused with muscimol before stress did not express a deficit in conditioning, whereas those infused with vehicle and stressed emitted fewer conditioned responses than unstressed vehicle controls. These data demonstrate that neuronal activity within the BLA during stress exposure is necessary to modulate learning 24 h later in a new context. Thus, the BLA is necessary to induce the long-term effect of stressful experience on conditioning regardless of sex and direction of modulation.
杏仁核基底外侧核（BLA）与应激后学习的调节有关。急性不可逃避应激可增强雄性大鼠的经典眨眼条件反射，而相同的应激源会损害雌性大鼠的眨眼条件反射。本实验直接评估了在应激暴露期间BLA失活是否会阻断应激诱导的雄性促进作用和雌性眨眼条件反射的延迟。为此，在急性应激源暴露前，通过注入GABA激动剂蝇蕈醇使BLA暂时失活。24小时后，所有大鼠在不同环境中接受训练。在应激事件前注入蝇蕈醇的雄性大鼠未表现出眨眼条件反射的促进作用，而注入赋形剂的雄性大鼠比未受应激的雄性大鼠发出更多的条件反应。在应激前注入蝇蕈醇的雌性大鼠在条件反射方面未表现出缺陷，而注入赋形剂并受到应激的雌性大鼠比未受应激的赋形剂对照发出的条件反应更少。这些数据表明，应激暴露期间BLA内的神经元活动对于在新环境中24小时后的学习调节是必要的。因此，无论性别和调节方向如何，BLA对于诱导应激经历对条件反射的长期影响都是必要的。
