Herry Cyril, Ciocchi Stephane, Senn Verena, Demmou Lynda, Müller Christian, Lüthi Andreas
Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
Nature. 2008 Jul 31;454(7204):600-6. doi: 10.1038/nature07166. Epub 2008 Jul 9.
Switching between exploratory and defensive behaviour is fundamental to survival of many animals, but how this transition is achieved by specific neuronal circuits is not known. Here, using the converse behavioural states of fear extinction and its context-dependent renewal as a model in mice, we show that bi-directional transitions between states of high and low fear are triggered by a rapid switch in the balance of activity between two distinct populations of basal amygdala neurons. These two populations are integrated into discrete neuronal circuits differentially connected with the hippocampus and the medial prefrontal cortex. Targeted and reversible neuronal inactivation of the basal amygdala prevents behavioural changes without affecting memory or expression of behaviour. Our findings indicate that switching between distinct behavioural states can be triggered by selective activation of specific neuronal circuits integrating sensory and contextual information. These observations provide a new framework for understanding context-dependent changes of fear behaviour.
在探索行为和防御行为之间进行切换对许多动物的生存至关重要，但特定神经回路是如何实现这种转变的尚不清楚。在这里，我们以小鼠恐惧消退及其情境依赖性恢复的相反行为状态为模型，表明高低恐惧状态之间的双向转变是由基底杏仁核两个不同神经元群体之间活动平衡的快速切换触发的。这两个群体被整合到与海马体和内侧前额叶皮质有不同连接的离散神经回路中。对基底杏仁核进行靶向和可逆的神经元失活可防止行为变化，而不影响记忆或行为表达。我们的研究结果表明，不同行为状态之间的切换可以由整合感觉和情境信息的特定神经回路的选择性激活触发。这些观察结果为理解恐惧行为的情境依赖性变化提供了一个新框架。
