Abstract
The glymphatic system is a brain-wide waste drainage system that promotes cerebrospinal fluid circulation through the brain to remove waste metabolites. Currently, the most common methods for assessing glymphatic function are ex vivo fluorescence microscopy of brain slices, macroscopic cortical imaging, and MRI. While all these methods have been crucial for expanding our understanding of the glymphatic system, new techniques are required to overcome their specific drawbacks. Here, we evaluate SPECT/CT imaging as a tool to assess glymphatic function in different anesthesia-induced brain states using two radiolabeled tracers, [111In]-DTPA and [99mTc]-NanoScan. Using SPECT, we confirmed the existence of brain state-dependent differences in glymphatic flow and we show brain state-dependent differences of CSF flow kinetics and CSF egress to the lymph nodes. We compare SPECT and MRI for imaging glymphatic flow and find that the two imaging modalities show the same overall pattern of CSF flow, but that SPECT was specific across a greater range of tracer concentrations than MRI. Overall, we find that SPECT imaging is a promising tool for imaging the glymphatic system, and that qualities such as high sensitivity and the variety of available tracers make SPECT imaging a good alternative for glymphatic research.
Original language | English |
---|---|
Journal | Journal of Cerebral Blood Flow and Metabolism |
Volume | 43 |
Issue number | 7 |
Number of pages | 13 |
ISSN | 0271-678X |
DOIs | |
Publication status | Published - 2023 |
Bibliographical note
Funding Information:Funding was provided by Lundbeck Foundation grant R386-2021-165, Novo Nordisk Foundation grant NNF20OC0066419, National Institutes of Health grant R01AT011439, National Institutes of Health grant U19NS128613, US Army Research Office grant MURI W911NF1910280, Human Frontier Science Program grant RGP0036, the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation, and Simons Foundation grant 811237. Acknowledgements
Keywords
- cerebrospinal fluid dynamics
- lymph nodes
- rat brain
- Waste clearance
- [111In]-DTPA