Laboratoire de Pharmacologie, Neurobiologie et Comportement, Centre National de la Recherche Scientifique et Technique, URAC 37, Cadi Ayyad Université, Marrakech, Maroc; Institut de Neurosciences de la Timone, UMR7289, Aix-Marseille Université & Centre National de la Recherche Scientifique, Marseille, France.
Laboratoire de Pharmacologie, Neurobiologie et Comportement, Centre National de la Recherche Scientifique et Technique, URAC 37, Cadi Ayyad Université, Marrakech, Maroc.
Neuroscience. 2019 Oct 15;418:166-176. doi: 10.1016/j.neuroscience.2019.08.018. Epub 2019 Sep 2.
Post-traumatic stress disorder (PTSD) is triggered by exposure to traumatic events, but not everyone who experiences trauma develops this disorder. Like humans, PTSD-like symptoms develop in some laboratory rodents (susceptible individuals), while others express less or no symptoms (resilient individuals). Here, considering (i) the putative causal role of fear conditioning in PTSD development and (ii) the involvement of the medial prefrontal cortex (mPFC) in the regulation of conditioned fear response, we tested whether trauma-associated changes in the mPFC may discriminate stress-resilient from stress-susceptible mice. From data on avoidance behavior (as a major symptom), we found that trauma-exposed mice displayed a bimodal distribution in their step-through latency, with low avoider (stress-resilient) individuals and high avoider (stress-susceptible) individuals. Dendrites of Golgi-Cox-stained neurons were analyzed in two parts of the mPFC: the prelimbic (PrL) and infralimbic (IL) areas. In the resilient phenotype, the total number of dendrites decreased in the PrL and increased in the IL; however, it decreased only in the IL in the susceptible phenotype compared to controls. These findings demonstrate that the type of post-trauma morphological changes in the mPFC is associated with susceptibility or resilience to trauma-related symptoms.
创伤后应激障碍（PTSD）是由暴露于创伤性事件引起的，但并非每个人经历创伤后都会发展出这种障碍。与人类一样，一些实验室啮齿动物（易感个体）会出现类似 PTSD 的症状，而另一些则表现出较少或没有症状（适应个体）。在这里，考虑到（i）恐惧条件作用在 PTSD 发展中的潜在因果作用，以及（ii）内侧前额叶皮层（mPFC）在调节条件性恐惧反应中的参与，我们测试了创伤相关的 mPFC 变化是否可以区分应激适应个体和应激易感个体。从回避行为（主要症状之一）的数据来看，我们发现，暴露于创伤的小鼠在穿过潜伏期表现出双峰分布，低回避者（应激适应个体）和高回避者（应激易感个体）。使用 Golgi-Cox 染色神经元的树突在 mPFC 的两个部分进行分析：额前皮质（PrL）和下边缘皮质（IL）。在适应表型中，PrL 中的树突总数减少，IL 中的树突总数增加；然而，与对照组相比，易感表型中仅在 IL 中减少。这些发现表明，mPFC 中创伤后形态变化的类型与对创伤相关症状的易感性或适应性有关。
