Neural Basis of Contextual Fear Conditioning

当受到痛苦或威胁的刺激时，我们的大脑会形成神经联系，将痛苦或威胁的刺激与其他无害的环境线索联系起来，这些线索可能会在以后成为警告信号。形成这种联想的过程被称为恐惧条件反射。一些受到条件反射的无害线索位于前景，与疼痛或威胁密切相关，而另一些则位于背景。对特定前景线索（如音调与脚部震动相结合）产生恐惧反应的神经系统被很好地理解并涉及杏仁核。然而，直到最近，人们对恐惧反应是如何与背景或上下文刺激相结合的知之甚少。在最近的研究中，勒杜博士发现海马体或杏仁核的损伤会干扰情境条件反射。本研究的目的是利用最先进的解剖学、生理学和行为学方法来了解杏仁核和海马体之间的神经相互作用如何有助于情境恐惧条件反射。具体来说，LeDoux博士将探索海马体形成对情境恐惧条件反射的贡献的解剖学连接（传入和传出）。这些研究可能对理解一系列复杂的情绪学习现象很重要。*** //

When exposed to a painful or threatening stimulus, our brains form neural associations that link the painful or threatening stimulus to other innocuous environmental cues that are present and that might later serve as warning signals. The process of forming such associations is referred to as fear conditioning. Some of the innocuous cues that get conditioned are in the foreground and are closely associated with the pain or threat, whereas others are in the background. The neural system underlying the conditioning of fear responses to specific foreground cues, such as a tone paired with footshock, is well understood and involve the amygdala. However, until recently, little was known about how fear reactions come to be coupled to background or contextual stimuli. In recent studies Dr. LeDoux found that lesions of hippocampus or amygdala interfered with contextual conditioning. The purpose of the proposed studies is to use state-of-the-art anatomical, physiological, and behavioral methods to understand how neural interactions between amygdala and hippocampus might contribute to contextual fear conditioning. Specifically, Dr. LeDoux will explore the anatomical connections (afferents and efferents) underlying the contribution of the hippocampal formation to contextual fear conditioning. These studies are likely to be important in understanding a host of complex emotional learning phenomena.*** //