D'Souza Deepthi, Sadananda Monika
Brain Research Laboratory, Biotechnology Unit, Department of Biosciences, Mangalore University, Mangalagangothri, India.
Ann Neurosci. 2017 Jul;24(3):136-145. doi: 10.1159/000477151. Epub 2017 Jul 24.
Depression often manifests during adolescence when the development and networking of social and emotional brain areas is being influenced by hormones. The Wistar Kyoto (WKY) rat has been proposed as an animal model of adolescent depression with various face, construct, and predictive validities for clinical depression having been established.
The influence of the estrous cycle on anxiety- and depression-like behaviors in female adolescents may be tested out further using this model.
Female adolescent WKY rats were tested for anxiety- and depression-like behaviors in the elevated plus maze and forced swim test (FST) during different phases of the estrous cycle with inbred, age-, and phase-matched Wistar rats as controls.
Wistars in proestrus-estrus demonstrated reduced anxiety levels. WKY also demonstrated increased open arm time and entries and closed arm time, but less than Wistars, and as closed arm entries remained unaffected, it did not translate into a lowering of the anxiety levels. Risk taking and risk assessment behaviors were not affected by estrous phases in WKY, though exploratory behavior was reduced in proestrus-estrus. In Wistars, increased risk taking and decreased risk assessment behaviors were observed during proestrus-estrus. Increased immobility in the FST, indicative of learned helplessness was not influenced by phase in the WKY, which was at variance with Wistars that demonstrated phase-specific differences.
Results indicate a masking effect of indicative hormones in this putative model of adolescent depression, with implications for an unravelling of the steroid milieu in predisposed adolescent depression and for taking phase-specific time windows into account for therapeutic interventions.
抑郁症常在青春期出现，此时社交和情感脑区的发育及神经网络正受激素影响。Wistar Kyoto（WKY）大鼠已被提议作为青少年抑郁症的动物模型，其对临床抑郁症具有多种表面效度、结构效度和预测效度。
可进一步利用该模型测试发情周期对雌性青少年焦虑样和抑郁样行为的影响。
在发情周期的不同阶段，对雌性青少年WKY大鼠在高架十字迷宫和强迫游泳试验（FST）中进行焦虑样和抑郁样行为测试，以近交、年龄和发情阶段匹配的Wistar大鼠作为对照。
处于动情前期 - 发情期的Wistar大鼠焦虑水平降低。WKY大鼠也表现出开放臂时间和进入次数增加以及封闭臂时间增加，但少于Wistar大鼠，且由于封闭臂进入次数未受影响，这并未转化为焦虑水平的降低。WKY大鼠的冒险和风险评估行为不受发情阶段影响，尽管在动情前期 - 发情期探索行为减少。在Wistar大鼠中，动情前期 - 发情期观察到冒险行为增加和风险评估行为减少。FST中不动时间增加表明存在习得性无助，这在WKY大鼠中不受发情阶段影响，这与表现出发情阶段特异性差异的Wistar大鼠不同。
结果表明在这个假定的青少年抑郁症模型中，指示性激素存在掩盖效应，这对于揭示易感青少年抑郁症中的类固醇环境以及在治疗干预中考虑发情阶段特异性时间窗口具有启示意义。
