Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, 301 Old Main Dr., College Station, TX, 77843-3474, USA.
Sci Rep. 2021 Apr 15;11(1):8215. doi: 10.1038/s41598-021-87559-3.
Environmental contexts can inform animals of potential threats, though it is currently unknown how context biases the selection of defensive behavior. Here we investigated context-dependent flight responses with a Pavlovian serial-compound stimulus (SCS) paradigm that evokes freeze-to-flight transitions. Similar to previous work in mice, we show that male and female rats display context-dependent flight-like behavior in the SCS paradigm. Flight behavior was dependent on contextual fear insofar as it was only evoked in a shock-associated context and was reduced in the conditioning context after context extinction. Flight behavior was only expressed to white noise regardless of temporal order within the compound. Nonetheless, rats that received unpaired SCS trials did not show flight-like behavior to the SCS, indicating it is associative. Finally, we show that pharmacological inactivation of two brain regions critical to the expression of contextual fear, the central nucleus of the amygdala (CeA) and bed nucleus of the stria terminalis (BNST), attenuates both contextual fear and flight responses. All of these effects were similar in male and female rats. This work demonstrates that contextual fear can summate with cued and innate fear to drive a high fear state and transition from post-encounter to circa-strike defensive modes.
环境背景可以向动物提示潜在威胁，尽管目前尚不清楚环境背景如何影响防御行为的选择。在这里，我们使用一种引发冻结-飞行转变的条件性关联复合刺激（SCS）范式，研究了依赖环境背景的飞行反应。与先前在小鼠中的研究相似，我们表明雄性和雌性大鼠在 SCS 范式中表现出依赖环境背景的类似飞行的行为。飞行行为取决于情境恐惧，因为它仅在与电击相关的情境中被引发，并且在情境消退后在条件情境中减少。飞行行为仅对白色噪声表现出来，而与复合刺激中的时间顺序无关。尽管如此，未接受配对 SCS 试验的大鼠对 SCS 没有表现出类似飞行的行为，表明这是一种联想性的反应。最后，我们表明，对杏仁中央核（CeA）和终纹床核（BNST）这两个对情境恐惧表达至关重要的脑区进行药理学失活，可减弱情境恐惧和飞行反应。这些效应在雄性和雌性大鼠中均相似。这项工作表明，情境恐惧可以与提示性和先天恐惧相加，以驱动高度的恐惧状态，并从遭遇后的防御模式过渡到接近攻击的防御模式。
