Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA.
Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
Biosensors (Basel). 2022 Aug 8;12(8):616. doi: 10.3390/bios12080616.
Anesthesia is often used in preclinical imaging studies that incorporate mouse or rat models. However, multiple reports indicate that anesthesia has significant physiological impacts. Thus, there has been great interest in performing imaging studies in awake, unanesthetized animals to obtain accurate results without the confounding physiological effects of anesthesia. Here, we describe a newly designed mouse holder that is interfaceable with existing MRI systems and enables awake in vivo mouse imaging. This holder significantly reduces head movement of the awake animal compared to previously designed holders and allows for the acquisition of improved anatomical images. In addition to applications in anatomical -weighted magnetic resonance imaging (MRI), we also describe applications in acquiring P spectra, manganese-enhanced magnetic resonance imaging (MEMRI) transport rates and resting-state functional magnetic resonance imaging (rs-fMRI) in awake animals and describe a successful conditioning paradigm for awake imaging. These data demonstrate significant differences in P spectra, MEMRI transport rates, and rs-fMRI connectivity between anesthetized and awake animals, emphasizing the importance of performing functional studies in unanesthetized animals. Furthermore, these studies demonstrate that the mouse holder presented here is easy to construct and use, compatible with standard Bruker systems for mouse imaging, and provides rigorous results in awake mice.
麻醉常用于包含小鼠或大鼠模型的临床前成像研究。然而，多项报告表明麻醉具有显著的生理影响。因此，人们非常感兴趣在清醒、未麻醉的动物中进行成像研究，以获得准确的结果，而不会受到麻醉的生理影响的干扰。在这里，我们描述了一种新设计的小鼠固定器，它可以与现有的 MRI 系统接口，并能够在清醒状态下对活体小鼠进行成像。与以前设计的固定器相比，该固定器显著减少了清醒动物的头部运动，并允许获得更好的解剖图像。除了在解剖加权磁共振成像（MRI）中的应用外，我们还描述了在清醒动物中获取 P 谱、锰增强磁共振成像（MEMRI）转运率和静息状态功能磁共振成像（rs-fMRI）的应用，并描述了一个成功的清醒成像条件范式。这些数据表明，麻醉和清醒动物之间的 P 谱、MEMRI 转运率和 rs-fMRI 连接存在显著差异，强调了在未麻醉动物中进行功能研究的重要性。此外，这些研究表明，本文提出的小鼠固定器易于构建和使用，与用于小鼠成像的标准布鲁克系统兼容，并为清醒小鼠提供了严格的结果。
