Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.
Neurobiol Dis. 2011 Oct;44(1):9-18. doi: 10.1016/j.nbd.2011.05.016. Epub 2011 Jun 6.
Zebrafish models of human neuropsychiatric diseases offer opportunities to identify novel therapeutic targets and treatments through phenotype-based genetic or chemical modifier screens. In order to develop an assay to detect rescue of zebrafish models of Parkinsonism, we characterized spontaneous zebrafish larval motor behavior from 3 to 9 days post fertilization in a microtiter plate format suitable for screening, and clarified the role of dopaminergic signaling in its regulation. The proportion of time that larvae spent moving increased progressively between 3 and 9 dpf, whereas their active velocity decreased between 5 and 6 dpf as sporadic burst movements gave way to a more mature beat-and-glide pattern. Spontaneous movement varied between larvae and during the course of recordings as a result of intrinsic larval factors including genetic background. Variability decreased with age, such that small differences between groups of larvae exposed to different experimental conditions could be detected robustly by 6 to 7 dpf. Suppression of endogenous dopaminergic signaling by exposure to MPP(+), haloperidol or chlorpromazine reduced mean velocity by decreasing the frequency with which spontaneous movements were initiated, but did not alter active velocity. The variability of mean velocity assays could be reduced by analyzing groups of larvae for each data point, yielding acceptable screening window coefficients; the sample size required in each group was determined by the magnitude of the motor phenotype in different models. For chlorpromazine exposure, samples of four larvae allowed robust separation of treated and untreated data points (Z=0.42), whereas the milder impairment provoked by MPP(+) necessitated groups of eight larvae in order to provide a useful discovery assay (Z=0.13). Quantification of spontaneous larval movement offers a simple method to determine functional integrity of motor systems, and may be a useful tool to isolate novel molecular modulators of Parkinsonism phenotypes.
斑马鱼人类神经精神疾病模型通过表型为基础的遗传或化学修饰物筛选，为鉴定新的治疗靶点和治疗方法提供了机会。为了开发一种检测帕金森病斑马鱼模型拯救的测定法，我们在微滴板格式中对 3 至 9 日龄受精卵的自发斑马鱼幼虫运动行为进行了特征描述，使其适合筛选，并阐明了多巴胺能信号在其调节中的作用。幼虫游动时间的比例从 3 日龄到 9 日龄逐渐增加，而它们的主动速度从 5 日龄到 6 日龄下降，因为零星爆发运动让位于更成熟的拍打滑行模式。由于包括遗传背景在内的内在幼虫因素，幼虫之间和记录过程中的自发运动存在差异。随着年龄的增长，变异性降低，因此，6 至 7 日龄时，暴露于不同实验条件下的幼虫群体之间的微小差异可以通过可靠地检测到。通过暴露于 MPP+、氟哌啶醇或氯丙嗪来抑制内源性多巴胺能信号，通过减少自发运动起始的频率来降低平均速度，但不会改变主动速度。通过为每个数据点分析幼虫组，可以降低平均速度测定的变异性，从而产生可接受的筛选窗口系数；每组所需的样本量取决于不同模型中运动表型的大小。对于氯丙嗪暴露，四个幼虫的样本允许对处理和未处理的数据点进行可靠的分离（Z=0.42），而 MPP+引起的较轻损伤需要八个幼虫的样本，以便提供有用的发现测定（Z=0.13）。自发幼虫运动的定量提供了一种简单的方法来确定运动系统的功能完整性，并且可能是分离帕金森病表型的新分子调节剂的有用工具。
