Jhou Thomas C, Fields Howard L, Baxter Mark G, Saper Clifford B, Holland Peter C
Behavioral Neuroscience Branch, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
Neuron. 2009 Mar 12;61(5):786-800. doi: 10.1016/j.neuron.2009.02.001.
Separate studies have implicated the lateral habenula (LHb) or amygdala-related regions in processing aversive stimuli, but their relationships to each other and to appetitive motivational systems are poorly understood. We show that neurons in the recently identified GABAergic rostromedial tegmental nucleus (RMTg), which receive a major LHb input, project heavily to midbrain dopamine neurons, and show phasic activations and/or Fos induction after aversive stimuli (footshocks, shock-predictive cues, food deprivation, or reward omission) and inhibitions after rewards or reward-predictive stimuli. RMTg lesions markedly reduce passive fear behaviors (freezing, open-arm avoidance) dependent on the extended amygdala, periaqueductal gray, or septum, all regions that project directly to the RMTg. In contrast, RMTg lesions spare or enhance active fear responses (treading, escape) in these same paradigms. These findings suggest that aversive inputs from widespread brain regions and stimulus modalities converge onto the RMTg, which opposes reward and motor-activating functions of midbrain dopamine neurons.
多项独立研究表明，外侧缰核（LHb）或杏仁核相关区域参与厌恶刺激的处理，但它们彼此之间以及与食欲动机系统的关系仍知之甚少。我们发现，最近确定的γ-氨基丁酸能的嘴内侧被盖核（RMTg）中的神经元，接受来自LHb的主要输入，大量投射到中脑多巴胺神经元，并在厌恶刺激（足部电击、电击预测线索、食物剥夺或奖励缺失）后表现出相位激活和/或Fos诱导，在奖励或奖励预测刺激后表现出抑制。RMTg损伤显著减少了依赖于扩展杏仁核、导水管周围灰质或隔区的被动恐惧行为（僵住、回避开放臂），所有这些区域都直接投射到RMTg。相比之下，在相同范式中，RMTg损伤使主动恐惧反应（踩踏板、逃跑）得以保留或增强。这些发现表明，来自广泛脑区和刺激模式的厌恶输入汇聚到RMTg，而RMTg与中脑多巴胺神经元的奖励和运动激活功能相反。
