Document text
Principal Investigator: Tod Edward Kippin
Organization: UNIVERSITY OF CALIFORNIA SANTA BARBARA
Fiscal Year: 2024
Award: $461,956
Funding agency: National Institute of Neurological Disorders and Stroke
Many leading questions in neuroscience such as how neurons encode experience, modify behavior, and
degenerate, require neural activity to be monitored throughout the brain in living animals. Neuronal activity is
tightly linked to an increase in intracellular calcium. Therefore, a cornerstone technology for monitoring neural
activity involves the use of genetically encoded fluorescent reporters of intracellular calcium. While fluorescent
tools for calcium sensing have proven immensely transformative for neuroscience research, optical approaches
do not allow neural activity to be monitored with brain-wide coverage or at any arbitrary depth. To address this
challenge, we will develop a new type of genetic sensor for visualizing cumulative calcium signals at a brain-
wide scale using magnetic resonance imaging (MRI). To construct these sensors, we will leverage water
channels known as aquaporins. We will build on our earlier discovery that aquaporins can be used to generate
diffusion-weighted MRI contrast by increasing the rate of water exchange across the cell membrane. Unlike
conventional MRI reporters, aquaporin-based contrast does not involve the use of metals, thereby permitting
fully autonomous, single-gene imaging with high sensitivity. To accomplish our goals, we propose two inter-
connected specific aims. In the first aim, we will develop aquaporin-based reporters of calcium signaling (ARCS)
by assembling a synthetic multi-gene cluster for coupling stimulus-evoked rises in intracellular calcium to
aquaporin expression. ARCS will permit neural activity to be integrated over defined stimulation epochs in awake,
freely behaving animals and subsequently read out by MRI. Following optimization in cell lines, we will validate
key performance attributes and safety profiles of ARCS in primary neurons. In the second aim, we will establish
in vivo functionality of ARCS by imaging local and brain-wide activation in response to well-established
neuromodulation paradigms involving chemogenetic and optogenetic inputs to the ventral tegmental area (VTA).
Concurrently, we will benchmark ARCS against multiple complementary readouts of neural activity including
blood oxygenation level dependent (BOLD) fMRI, calcium-sensing fluorescence reporters, and c-fos
immunohistochemistry. The anticipated outcome of this project is an optimized and well-validated set of genetic
tools that will provide neuroscientists with new avenues for unbiased exploration of neural networks involved in
coordinating everything from sensory function to behavior generation.
Terms: <Address><Animal Model><Animal Models and Related Studies><Animals><Aquaporins><BBB crossing><Behavior><Benchmarking><Best Practice Analysis><Body Tissues><Brain><Brain Mapping><Brain Nervous System><Calcium><Calcium Ion Signaling><Calcium Signaling><Cell Communication and Signaling><Cell Line><Cell Signaling><Cell membrane><Cell model><CellLine><Cellular model><Coupling><Cytoplasmic Membrane><DWI (diffusion weighted imaging)><DWI-MRI><Decision Making><Development><Diffusion MRI><Diffusion Magnetic Resonance Imaging><Diffusion Weighted MRI><Diffusion weighted imaging><Diffusion-weighted Magnetic Resonance Imaging><Encephalon><Engineering><FOS gene><Fiber><Fluorescence><Functional MRI><Functional Magnetic Resonance Imaging><G0S7><Gene Cluster><Generations><Genes><Genetic><Goals><Hydrogen Oxide><Image><Immunohistochemistry><Immunohistochemistry Cell/Tissue><Immunohistochemistry Staining Method><Intracellular Communication and Signaling><Link><Location><MR Imaging><MR Tomography><MRI><MRIs><Magnetic Resonance Imaging><Maps><Medical Imaging, Magnetic Resonance / Nuclear Magnetic Resonance><Memory><Metals><Methods><Mice><Mice Mammals><Molecular><Monitor><Murine><Mus><NMR Imaging><NMR Tomography><Nerve Cells><Nerve Unit><Neural Cell><Neurocyte><Neurons><Neurosciences><Neurosciences Research><Nuclear Magnetic Resonance Imaging><Nucleus Accumbens><Operative Procedures><Operative Surgical Procedures><Optics><Organism><Osmosis><Outcome><Output><Pattern><Performance><Photometry><Physiologic pulse><Plasma Membrane><Protooncogene FOS><Pulse><Reporter><Reporter Genes><Resolution><Rewards><Safety><Sensorimotor functions><Sensory><Serotyping><Signal Transduction><Signal Transduction Systems><Signaling><Specificity><Stimulus><Strains Cell Lines><Surgical><Surgical Interventions><Surgical Procedure><System><Techniques><Technology><Testing><Tissues><Toxic effect><Toxicities><Transgenic Organisms><Translating><Ventral Tegmental Area><Vertebrate Animals><Vertebrates><Viral><Visualization><Water><Water Channel Proteins><Work><Zeugmatography><awake><benchmark><biological signal transduction><blood oxygen level dependent><blood oxygenation level dependent><blood-brain barrier crossing><bloodbrain barrier crossing><brain volume><c fos><c-fos Gene><c-fos Proto-Oncogenes><cell type><cultured cell line><dMRI><developmental><diffusion tensor imaging><experience><fMRI><fluorescence imaging><fluorescent imaging><genetic approach><genetic strategy><hemodynamics><imaging><in vivo><learned behavior><learning behavior><lens><lenses><living system><metallicity><model of animal><motivated behavior><mouse model><multiphoton excitation microscopy><multiphoton microscopy><murine model><neural><neural control><neural correlate><neural imaging><neural network><neural regulation><neuro-imaging><neuroimaging><neurological imaging><neuromodulation><neuromodulatory><neuronal><neuroregulation><optical><optogenetics><pharmacologic><plasmalemma><resolutions><response><reward circuitry><sensor><surgery><synthetic biology><tool><transgenic><uptake><v-FOS FBJ Murine Osteosarcoma Viral Oncogene Homolog><ventral tegmentum><vertebrata><water channel><water transporter>