Department of Psychology, University of California, Los Angeles, Los Angeles, United States.
University of California, Los Angeles, Los Angeles, United States.
Elife. 2021 Sep 1;10:e69178. doi: 10.7554/eLife.69178.
Escape from threats has paramount importance for survival. However, it is unknown if a single circuit controls escape vigor from innate and conditioned threats. Cholecystokinin (cck)-expressing cells in the hypothalamic dorsal premammillary nucleus (PMd) are necessary for initiating escape from innate threats via a projection to the dorsolateral periaqueductal gray (dlPAG). We now show that in mice PMd-cck cells are activated during escape, but not other defensive behaviors. PMd-cck ensemble activity can also predict future escape. Furthermore, PMd inhibition decreases escape speed from both innate and conditioned threats. Inhibition of the PMd-cck projection to the dlPAG also decreased escape speed. Intriguingly, PMd-cck and dlPAG activity in mice showed higher mutual information during exposure to innate and conditioned threats. In parallel, human functional magnetic resonance imaging data show that a posterior hypothalamic-to-dlPAG pathway increased activity during exposure to aversive images, indicating that a similar pathway may possibly have a related role in humans. Our data identify the PMd-dlPAG circuit as a central node, controlling escape vigor elicited by both innate and conditioned threats.
逃避威胁对生存至关重要。然而,目前尚不清楚是否有一个单一的回路控制着对先天和条件威胁的逃避力度。下丘脑背侧前乳头核(PMd)中表达胆囊收缩素(CCK)的细胞对于通过投射到外侧导水管周围灰质(dlPAG)来启动对先天威胁的逃避是必需的。我们现在表明,在逃避过程中,PMd-CCK 细胞被激活,但其他防御行为则不会。PMd-CCK 集合活动也可以预测未来的逃避。此外,PMd 抑制会降低对先天和条件威胁的逃避速度。PMd-CCK 投射到 dlPAG 的抑制也降低了逃避速度。有趣的是,在暴露于先天和条件威胁时,小鼠的 PMd-CCK 和 dlPAG 活动显示出更高的互信息。与此同时,人类功能磁共振成像数据显示,后下丘脑到 dlPAG 的通路在暴露于厌恶图像时活动增加,表明类似的通路可能在人类中具有相关作用。我们的数据确定了 PMd-dlPAG 回路作为一个中央节点,控制着先天和条件威胁引发的逃避力度。