Cell Biology and Gene Expression Section, National Institute on Aging, National Institutes of Health;
Cell Biology and Gene Expression Section, National Institute on Aging, National Institutes of Health.
J Vis Exp. 2021 Feb 18(168). doi: 10.3791/62128.
Parkinson's disease (PD) is a progressive disorder traditionally defined by resting tremor and akinesia, primarily due to loss of dopaminergic neurons in the substantia nigra. Affected brain areas display intraneuronal fibrillar inclusions consisting mainly of alpha-synuclein (asyn) proteins. No animal model thus far has recapitulated all characteristics of this disease. Here, we describe the use of stereotaxic injection to deliver chemicals, proteins, or viral vectors intracranially in order to mimic various aspects of PD. These methods are well-established and widely used throughout the PD field. Stereotaxic injections are incredibly flexible; they can be adjusted in concentration, age of animal used for injection, brain area targeted and in animal species used. Combinations of substances allow for rapid variations to assess treatments or alter severity of the pathology or behavioral deficits. By injecting toxins into the brain, we can mimic inflammation and/or a severe loss of dopaminergic neurons resulting in substantial motor phenotypes. Viral vectors can be used to transduce cells to mimic genetic or mechanistic aspects. Preformed fibrillar asyn injections best recapitulate the progressive phenotype over an extended period of time. Once these methods are established, it can be economical to generate a new model compared to creating a new transgenic line. However, this method is labor intensive as it requires 30 minutes to four hours per animal depending on the model used. Each animal will have a slightly different targeting and therefore create a diverse cohort which on one hand can be challenging to interpret results from; on the other hand, help mimic a more realistic diversity found in patients. Mistargeted animals can be identified using behavioral or imaging readouts, or only after being sacrificed leading to smallercohort size after the study has already been concluded. Overall, this method is a rudimentary but effective way to assess a diverse set of PD aspects.
帕金森病（PD）是一种进行性疾病，传统上以静止性震颤和运动迟缓为特征，主要由于黑质多巴胺能神经元丧失所致。受影响的大脑区域显示出主要由α-突触核蛋白（asyn）蛋白组成的神经元内纤维包涵体。迄今为止，没有任何动物模型能够再现这种疾病的所有特征。在这里，我们描述了使用立体定向注射将化学物质、蛋白质或病毒载体颅内递送到以模拟 PD 的各个方面。这些方法已经得到很好的确立，并在 PD 领域得到广泛应用。立体定向注射具有极高的灵活性；它们可以在浓度、用于注射的动物年龄、靶向的脑区和使用的动物物种方面进行调整。物质的组合可以快速变化，以评估治疗方法或改变病理学或行为缺陷的严重程度。通过将毒素注射到大脑中，我们可以模拟炎症和/或多巴胺能神经元的严重丧失，导致显著的运动表型。病毒载体可用于转导细胞以模拟遗传或机制方面。预形成的纤维状 asyn 注射最能在较长时间内再现进行性表型。一旦这些方法建立起来，与创建新的转基因系相比，生成新模型可能会更经济。然而，这种方法劳动强度大，因为它需要根据使用的模型为每只动物花费 30 分钟到四个小时。每个动物的靶点都会略有不同，因此会产生一个多样化的队列，一方面可能难以解释结果；另一方面，有助于模拟患者中更真实的多样性。通过行为或成像读数，或者仅在牺牲后才能识别出靶向错误的动物，这会导致研究结束后队列规模较小。总的来说，这种方法是评估 PD 多方面的一种基本但有效的方法。
