Egeland M, Guinaudie C, Du Preez A, Musaelyan K, Zunszain P A, Fernandes C, Pariante C M, Thuret S
Department of Psychological Medicine, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
Transl Psychiatry. 2017 Apr 25;7(4):e1101. doi: 10.1038/tp.2017.68.
Numerous studies have examined links between postnatal neurogenesis and depression using a range of experimental methods to deplete neurogenesis. The antimitotic drug temozolomide (TMZ) has previously been used successfully as an experimental tool in animals to deplete adult neurogenesis and is used regularly on human patients as a standard chemotherapy for brain cancer. In this study, we wanted to evaluate whether TMZ as a model for chemotherapy treatment could affect parameters related to depression in an animal model. Prevalence rates of depression in patients is thought to be highly underdiagnosed, with some studies reporting rates as high as 90%. Results from this study in mice, treated with a regimen of TMZ similar to humans, exhibited behavioural and biochemical changes that have relevance to the development of depression. In particular, behavioural results demonstrated robust deficits in processing novelty and a significant increase in the corticosterone response. Quantification of neurogenesis using a novel sectioning method, which clearly evaluates dorsal and ventral neurogenesis separately, showed a significant correlation between the level of ventral neurogenesis and the corticosterone response. Depression is a complex disorder with discoveries regarding its neurobiology and how it relates to behaviour being only in their infancy. The findings presented in this study demonstrate that chemotherapy-induced decreases in neurogenesis results in previously unreported behavioural and biochemical consequences. These results, we argue, are indicative of a biological mechanism, which may contribute to the development of depression in patients being treated with chemotherapy and is separate from the mental distress resulting from a cancer diagnosis.
众多研究使用一系列耗尽神经发生的实验方法,探究了产后神经发生与抑郁症之间的联系。抗有丝分裂药物替莫唑胺(TMZ)此前已成功用作动物实验工具来耗尽成年神经发生,并且在人类患者中作为脑癌的标准化疗药物被定期使用。在本研究中,我们想评估TMZ作为化疗治疗模型是否会影响动物模型中与抑郁症相关的参数。据认为,患者中抑郁症的患病率被严重漏诊,一些研究报告的患病率高达90%。在本研究中,用与人类相似的TMZ方案治疗的小鼠所得到的结果显示出与抑郁症发展相关的行为和生化变化。特别是,行为结果表明在处理新奇事物方面存在明显缺陷,并且皮质酮反应显著增加。使用一种新颖的切片方法对神经发生进行量化,该方法能清晰地分别评估背侧和腹侧神经发生,结果显示腹侧神经发生水平与皮质酮反应之间存在显著相关性。抑郁症是一种复杂的疾病,关于其神经生物学以及它与行为的关系的发现尚处于起步阶段。本研究中呈现的结果表明,化疗引起的神经发生减少会导致此前未报告的行为和生化后果。我们认为,这些结果表明存在一种生物学机制,这可能导致接受化疗的患者患上抑郁症,并且与癌症诊断所导致的精神痛苦无关。