The aim of this study was to explore the neurobiological background of individual susceptibility and resistance to the development of posttraumatic stress disorder (PTSD)-like behaviours. Rats were divided into susceptible, PTSD(+), and resistant, PTSD(-), groups based on freezing duration during exposure to aversive context and the time spent in the central area in open field test one week after threefold stress experience (modified single prolonged stress). PTSD(-) rats showed increased concentrations of corticosterone in plasma and changes in GAD67 expression: decreased in the infralimbic cortex (IL) and increased in the lateral amygdala (LA), dentate gyrus (DG), and CA1 area of the hippocampus. Moreover, in this group, we found an increase in the number of CRF-positive nuclei in the parvocellular neurons of the paraventricular hypothalamic nucleus (pPVN). The PTSD(+) group, compared to PTSD(-) rats, had decreased concentrations of corticosterone in plasma and reduced CRF expression in the pPVN, higher CRF expression in the CA1, increased expression of CRF-positive nuclei and GR receptors in the CA3 area of the hippocampus, and increased expression of GR receptors in the DG and the central amygdala (CeA). Biochemical analysis showed higher concentrations of noradrenaline, glutamic acid in the dorsal hippocampus and amygdala and lower levels of dopamine and its metabolites in the amygdala of the PTSD(+) group than in the PTSD(-) group. The study revealed different behavioural and biochemical profiles of PTSD(+) and PTSD(-) rats and suggested that individual differences in hypothalamic-pituitary-adrenal (HPA) axis activity may determine hippocampal- and amygdala-dependent memory and fear processing.

本研究的目的是探索个体对创伤后应激障碍 (PTSD) 样行为发展的易感性和抵抗性的神经生物学背景。将大鼠分为易感组、PTSD(+) 和抗性、PTSD(-) 组，根据暴露于厌恶环境期间的冻结持续时间和在三倍压力经历后一周在开放场测试中心区域花费的时间（修改单长时间的压力）。PTSD(-) 大鼠血浆中皮质酮浓度增加，GAD67 表达发生变化：边缘下皮层 (IL) 减少，外侧杏仁核 (LA)、齿状回 (DG) 和海马 CA1 区增加。而且，在这个群体中，我们发现室旁下丘脑核 (pPVN) 的细小细胞神经元中 CRF 阳性细胞核的数量增加。与 PTSD(-) 大鼠相比，PTSD(+) 组血浆中皮质酮浓度降低，pPVN 中 CRF 表达降低，CA1 中 CRF 表达更高，CA3 中 CRF 阳性细胞核和 GR 受体的表达增加海马区，以及 DG 和中央杏仁核 (CeA) 中 GR 受体的表达增加。生化分析显示，与 PTSD(-) 组相比，PTSD(+) 组背侧海马和杏仁核中去甲肾上腺素、谷氨酸的浓度更高，而杏仁核中多巴胺及其代谢物的含量更低。