The amygdala attributes valence and emotional salience to environmental stimuli and regulates how these stimuli affect behavior. Within the amygdala, a distinct class of evolutionarily conserved neurons form the intercalated cell (ITC) clusters, mainly located around the boundaries of the lateral and basal nuclei. Here, we review the anatomical, physiological and molecular characteristics of ITCs, and detail the organization of ITC clusters and their connectivity with one another and other brain regions. We describe how ITCs undergo experience-dependent plasticity and discuss emerging evidence demonstrating how ITCs are innervated and functionally regulated by neuromodulatory systems. We summarize recent findings showing that experience alters the balance of activity between different ITC clusters, thereby determining prevailing behavioral output. Finally, we propose a model in which ITCs form a key system for integrating divergent inputs and orchestrating brain-wide circuits to generate behavioral states attuned to current environmental circumstances and internal needs.

杏仁核将效价和情绪显著性归因于环境刺激，并调节这些刺激如何影响行为。在杏仁核内，一类独特的进化上保守的神经元形成闰细胞 （ITC） 簇，主要位于外侧核和基底核的边界周围。在这里，我们回顾了 ITC 的解剖学、生理学和分子特征，并详细介绍了 ITC 集群的组织及其与其他大脑区域之间的连接。我们描述了 ITC 如何经历经验依赖性可塑性，并讨论了证明 ITC 如何受神经调节系统支配和功能调节的新证据。我们总结了最近的研究结果，表明经验改变了不同 ITC 集群之间的活动平衡，从而决定了主要的行为输出。最后，我们提出了一个模型，其中 ITC 形成一个关键系统，用于整合不同的输入并协调全脑回路以产生与当前环境环境和内部需求相适应的行为状态。