Research in the Turnbull Lab


Contrast enhanced micro-MRI methods are being developed to analyze the developing vascular system in mouse embryos.

The Turnbull laboratory has pioneered ultrasound biomicroscopy (UBM) imaging and Doppler-based blood flow approaches for in vivo analysis of mouse cardiovascular development from the earliest embryonic stages of cardiac function. These methods are now being employed in a number of laboratories for in utero cardiac imaging and hemodynamic analysis. Recently, we developed 3D approaches for analyzing heart and vascular development, using intravascular contrast agents to produce high-resolution, 3D images with both UBM and magnetic resonance micro-imaging (micro-MRI). These approaches are now being extended to enable cell-specific vascular imaging, using contrast agents targeted to membrane proteins expressed in endothelial cells of transgenic mouse embryos. Taken together, our methods are providing in vivo approaches for analyzing cardiovascular development in the mouse, from structure and function at the whole organism level, to the cellular and molecular levels through targeted contrast-enhanced imaging.

 

Statistical mapping from MEMRI data enables quantitative analysis of sound-evoked activity, as shown in the tonotopic maps corresponding to 16 (green) and 40 (red) kHz.


In the mouse nervous system, the Turnbull laboratory has developed a unique and powerful set of in vivo analytical tools based on UBM and micro-MRI imaging technologies. UBM has been developed for in utero brain imaging and image-guided injection, enabling cell transplantation and genetic gain-of-function studies with retroviruses. Micro-MRI methods are providing a wealth of 3D anatomical and functional data from the fetal to adult mouse brain, allowing longitudinal analysis of brain development, the progression of brain cancer and neurodegenerative disease, and in vivo phenotype analysis of a wide range of neurological mouse mutants. Moving beyond anatomical studies, we have developed functional MRI methods, including perfusion MRI protocols for quantifying vascular density and tumor blood flow, and manganese-enhanced MRI (MEMRI) for neural activity mapping in the mouse brain from early postnatal stages. Finally, we are investigating several MRI contrast enhancement methods for stem cell labeling and tracking, including externally applied nano-to-micrometer sized iron-oxide particles for in vivo cell tagging, and transgenic expression of proteins involved in paramagnetic metal internalization and storage as a genetic approach for controlling cellular MRI contrast in the developing mouse brain.