Brain network reorganization differs in response to stress in rats genetically predisposed to depression and stress-resilient rats
Brain network reorganization differs in response to stress in rats genetically predisposed to depression and stress-resilient rats
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DOI：
10.1038/tp.2016.233
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发表时间：
2016-12-06
影响因子：
6.8
通讯作者：
Sartorius，A.
中科院分区：
文献类型：
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作者：
Gass，N.;Becker，R.;Sartorius，A.
难治性抑郁症（TRD）仍然是一个紧迫的临床问题。优化治疗需要更好地定义相关大脑回路的特异性。为负性认知状态（NC）饲养的大鼠品系代表了TRD的遗传动物模型，具有较高的表面、结构和预测效度。反之亦然，积极认知状态（PC）应变代表了压力弹性表型。虽然NC大鼠表现出抑郁样行为，但某些症状（如快感缺乏）需要外部触发，即压力事件，这与人类相似，当压力事件在遗传易感个体中诱导抑郁发作时（基因-环境相互作用）。我们的目的是在脑网络重组的水平上区分神经生物学易感性和抑郁病理学。为此，在9.4特斯拉扫描仪上采集NC（N = 11）和PC（N = 7）大鼠在应激事件前后的静息态功能磁共振成像时间序列。我们使用图论分析方法来计算脑网络的全局和局部属性。菌株之间的总体特征没有差异。在局部水平上，在风险应变的响应的特点是增加节点间的作用和减少局部集群和效率的前扣带皮层（ACC）和前边缘皮层相比，应力弹性应变。我们认为，这些前额叶区域节点间作用的增强可能是由于它们与杏仁核和其他类似默认模式的网络中心的连接增强了它们的一些长程连接，这可能会产生一种偏向，以关注抑郁症的负面信息特征。
Treatment-resistant depression (TRD) remains a pressing clinical problem. Optimizing treatment requires better definition of the specificity of the involved brain circuits. The rat strain bred for negative cognitive state (NC) represents a genetic animal model of TRD with high face, construct and predictive validity. Vice versa, the positive cognitive state (PC) strain represents a stress-resilient phenotype. Although NC rats show depressive-like behavior, some symptoms such as anhedonia require an external trigger, ie a stressful event, which is similar to humans when stressful event induces a depressive episode in genetically predisposed individuals (gene–environment interaction). We aimed to distinguish neurobiological predisposition from the depressogenic pathology at the level of brain-network reorganization. For this purpose, resting-state functional magnetic resonance imaging time series were acquired at 9.4 Tesla scanner in NC (N= 11) and PC (N= 7) rats before and after stressful event. We used a graph theory analytical approach to calculate the brain-network global and local properties. There was no difference in the global characteristics between the strains. At the local level, the response in the risk strain was characterized with an increased internodal role and reduced local clustering and efficiency of the anterior cingulate cortex (ACC) and prelimbic cortex compared to the stress-resilient strain. We suggest that the increased internodal role of these prefrontal regions could be due to the enhancement of some of their long-range connections, given their connectivity with the amygdala and other default-mode-like network hubs, which could create a bias to attend to negative information characteristic for depression.