Neural correlates of distinct levels of predatory threat in dorsal periaqueductal grey neurons.
Neural correlates of distinct levels of predatory threat in dorsal periaqueductal grey neurons.
复制标题
背侧导水管周围灰色神经元中不同捕食威胁水平的神经相关性。
DOI：
10.1111/ejn.15633
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Bindi RP
中科院分区：
文献类型：
--
作者：
Bindi RP
中脑导水管周围灰质（PAG）是整合捕食性威胁的重要部位。然而，目前尚不清楚PAG中与捕食者相关的激活是否主要反映了威胁本身，从而可以区分不同程度的威胁，或者更确切地说，反映了以威胁为导向的行为，PAG可能会编排不同类型的防御剧目。为了解决这个问题，我们进行了背PAG神经元的细胞外记录在自由行为的大鼠和检查神经元和行为的反应，刺激条件下具有不同程度的掠夺性威胁。将动物依次暴露于非威胁性刺激熟悉环境（暴露于习惯环境）和新的非威胁性刺激（即，玩具动物-长毛绒）和具有高（暴露于活猫）、中等（暴露于猫刚访问过的环境，具有残留的捕食者气味）和低（第二天暴露于捕食环境）水平的捕食威胁的条件。为了测试威胁刺激和行为对射击率变化的贡献，我们采用了泊松广义线性模型回归，使用不同的捕食者刺激条件和防御剧目作为预测变量。分析显示，不同的捕食者刺激条件比不同的防御系统更能预测射击率的变化（主要是威胁引起的增加）。因此，背侧PAG可能编码不同程度的捕食威胁，而不是直接协调不同的威胁导向行为。目前的研究结果打开了有趣的视角，以研究背侧PAG在介导恐惧诱导刺激的原始情绪和认知反应中的作用。
The dorsal periaqueductal grey (PAG) is an important site for integrating predatory threats. However, it remains unclear whether predator‐related activation in PAG primarily reflects threat itself and thus can distinguish between various degrees of threat, or rather reflects threat‐oriented behaviours, with the PAG potentially orchestrating different types of defensive repertoire. To address this issue, we performed extracellular recording of dorsal PAG neurons in freely behaving rats and examined neuronal and behavioural responses to stimulus conditions with distinct levels of predatory threat. Animals were sequentially exposed to a nonthreatening stimulus familiar environment (exposure to habituated environment) and to a novel nonthreatening stimulus (i.e., a toy animal—plush) and to conditions with high (exposure to a live cat), intermediate (exposure to the environment just visited by the cat, with remnant predator scent), and low (exposure on the following day to the predatory context) levels of predatory threat. To test for contributions of both threat stimuli and behaviour to changes in firing rate, we applied a Poisson generalized linear model regression, using the different predator stimulus conditions and defensive repertoires as predictor variables. Analysis revealed that the different predator stimulus conditions were more predictive of changes in firing rate (primarily threat‐induced increases) than the different defensive repertoires. Thus, the dorsal PAG may code for different levels of predatory threat, more than it directly orchestrates distinct threat‐oriented behaviours. The present results open interesting perspectives to investigate the role of the dorsal PAG in mediating primal emotional and cognitive responses to fear‐inducing stimuli.