A Mouse Holder for Awake Functional Imaging in Unanesthetized Mice: Applications in <sup>31</sup>P Spectroscopy, Manganese-Enhanced Magnetic Resonance Imaging Studies, and Resting-State Functional Magnetic Resonance Imaging
Lindsay C. Fadel,
Ivany V. Patel,
Jonathan Romero,
I-Chih Tan,
Shelli R. Kesler,
Vikram Rao,
S. A. Amali S. Subasinghe,
Russell S. Ray,
Jason T. Yustein,
Matthew J. Allen,
Brian W. Gibson,
Justin J. Verlinden,
Stanley Fayn,
Nicole Ruggiero,
Caitlyn Ortiz,
Elizabeth Hipskind,
Aaron Feng,
Chijindu Iheanacho,
Alex Wang,
Robia G. Pautler
Affiliations
Lindsay C. Fadel
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Ivany V. Patel
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Jonathan Romero
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
I-Chih Tan
Bioengineering Core, Advanced Technology Core, Baylor College of Medicine, Houston, TX 77030, USA
Shelli R. Kesler
School of Nursing, University of Texas at Austin, Austin, TX 78712, USA
Vikram Rao
School of Nursing, University of Texas at Austin, Austin, TX 78712, USA
S. A. Amali S. Subasinghe
Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
Russell S. Ray
Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
Jason T. Yustein
Cancer and Cell Biology Program, Baylor College of Medicine, Houston, TX 77030, USA
Matthew J. Allen
Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
Brian W. Gibson
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Justin J. Verlinden
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Stanley Fayn
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Nicole Ruggiero
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Caitlyn Ortiz
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Elizabeth Hipskind
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Aaron Feng
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Chijindu Iheanacho
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Alex Wang
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
Robia G. Pautler
Department Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
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 T2-weighted magnetic resonance imaging (MRI), we also describe applications in acquiring 31P 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 31P 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.
