Data_Sheet_1_Systematic Review: Anaesthetic Protocols and Management as Confounders in Rodent Blood Oxygen Level Dependent Functional Magnetic Resonance Imaging (BOLD fMRI)–Part A: Effects of Changes in Physiological Parameters.PDF

Background: To understand brain function in health and disease, functional magnetic resonance imaging (fMRI) is widely used in rodent models. Because animals need to be immobilised for image acquisition, fMRI is commonly performed under anaesthesia. The choice of anaesthetic protocols and may affect fMRI readouts, either directly or via changing physiological balance, and thereby threaten the scientific validity of fMRI in rodents.
Methods: The present study systematically reviewed the literature investigating the influence of different anaesthesia regimes and changes in physiological parameters as confounders of blood oxygen level dependent (BOLD) fMRI in rats and mice. Four databases were searched, studies selected according to pre-defined criteria, and risk of bias assessed for each study. Results are reported in two separate articles; this part of the review focuses on effects of changes in physiological parameters.
Results: A total of 121 publications was included, of which 49 addressed effects of changes in physiological parameters. Risk of bias was high in all included studies. Blood oxygenation [arterial partial pressure of oxygen (paO2)], ventilation [arterial partial pressure of carbon dioxide (paCO2)] and arterial blood pressure affected BOLD fMRI readouts across various experimental paradigms.
Conclusions: Blood oxygenation, ventilation and arterial blood pressure should be monitored and maintained at stable physiological levels throughout experiments. Appropriate anaesthetic management and monitoring are crucial to obtain scientifically valid, reproducible results from fMRI studies in rodent models.

研究背景：为探究健康与疾病状态下的脑功能机制，功能性磁共振成像（functional magnetic resonance imaging，fMRI）已被广泛应用于啮齿类动物模型。由于图像采集过程中需固定实验动物，fMRI通常需在麻醉状态下开展。麻醉方案的选择可通过直接作用或改变生理稳态的方式影响fMRI信号采集结果，进而威胁啮齿类fMRI研究的科学可靠性。
研究方法：本研究对相关文献进行了系统综述，旨在探讨不同麻醉方案与生理参数变化作为血氧水平依赖（blood oxygen level dependent，BOLD）fMRI研究混杂因素的影响，研究对象为大鼠与小鼠。本研究共检索4个数据库，依据预先设定的标准筛选纳入文献，并对每项研究的偏倚风险进行评估。研究结果分为两篇文章发表；本次综述内容聚焦于生理参数变化所产生的影响。
研究结果：最终共纳入121篇文献，其中49篇探讨了生理参数变化的影响。所有纳入研究的偏倚风险均较高。血氧状态[动脉血氧分压（arterial partial pressure of oxygen，paO2）]、通气状态[动脉血二氧化碳分压（arterial partial pressure of carbon dioxide，paCO2）]与动脉血压，在多种实验范式中均会对BOLD fMRI信号采集结果产生影响。
研究结论：在整个实验过程中，需对血氧状态、通气状态与动脉血压进行监测，并维持其处于稳定的生理水平。合理的麻醉管理与监测手段，对于从啮齿类动物模型的fMRI研究中获取具备科学可靠性与可重复性的研究结果至关重要。