Noradrenaline modulates global brain states and diverse behaviors through what is traditionally believed to be a homogeneous cell population in the brainstem locus coeruleus (LC). However, it is unclear how LC coordinates disparate behavioral functions. We report a modular LC organization in rats, endowed with distinct neural projection patterns and coding properties for flexible specification of opposing behavioral learning states. LC projection mapping revealed functionally distinct cell modules with specific anatomical connectivity. An amygdala-projecting ensemble promoted aversive learning, while an independent medial prefrontal cortex-projecting ensemble extinguished aversive responses to enable flexible behavior. LC neurons displayed context-dependent inter-relationships, with moderate, discrete activation of distinct cell populations by fear or safety cues and robust, global recruitment of most cells by strong aversive stimuli. These results demonstrate a modular organization in LC in which combinatorial activation modes are coordinated with projection- and behavior-specific cell populations, enabling adaptive tuning of emotional responding and behavioral flexibility.

中文翻译：

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脑干去甲肾上腺素系统的模块化组织协调了相反的学习状态。

去甲肾上腺素通过传统上被认为是脑干轨迹蓝斑（LC）中的同质细胞群体来调节整体脑部状态和多种行为。但是，尚不清楚LC如何协调不同的行为功能。我们报告了大鼠的模块化LC组织，具有独特的神经投射模式和编码特性，可以灵活地指定对立的行为学习状态。LC投影图显示功能不同的细胞模块具有特定的解剖学连接性。杏仁核投射的合奏促进厌恶学习，而独立的内侧前额叶皮层投射的合奏消灭厌恶反应，以实现灵活的行为。LC神经元显示出上下文相关的相互关系，其中中等，通过恐惧或安全提示离散地激活不同细胞群，并通过强烈的厌恶刺激来稳定，全局地招募大多数细胞。这些结果证明了LC中的模块化组织，其中组合激活模式与特定于投影和行为的细胞群体协调，从而能够自适应调节情绪反应和行为灵活性。