Chronic Intraventricular Cannulation for the Study of Glymphatic Transport

Glymphatic transport in rodents has primarily been studied using cisterna magna cannulation (CMC), a minimally invasive method for cerebrospinal fluid (CSF) tracers’ infusion. However, CMC is suboptimal due to the lack of bony structures to stabilize the cannula, leading to potential movement artifacts. Here, we present an alternative approach involving chronic cannulation of the lateral ventricles of mice for CSF tracer delivery. A direct comparison demonstrated that intraventricular cannulation (IVC) reproduces CMC results in vivo, including perivascular labeling of the middle cerebral artery, which was further confirmed by ex vivo analysis. IVC enables tracer infusion in awake mice, facilitating glymphatic transport studies in conjunction with behavioral assessments that were previously unattainable. Additionally, IVC supports repeated infusions in awake animals, offering the potential to reduce the number of experimental animals required. This study establishes IVC as a robust alternative for studying glymphatic transport and associated physiological processes. Significance Statement Refinement in tracer delivery methods is crucial for advancing the study of brain fluid transport, a field traditionally reliant on these techniques to visualize cerebrospinal fluid (CSF) movement. Cisterna magna cannulation (CMC) has become the gold standard for assessing glymphatic system function due to its minimal invasive nature and high reproducibility. In this study, we present an alternative method for tracer delivery to the lateral ventricles through the placement of chronically implanted cannulas. Additionally, we demonstrate that intraventricular cannulation (IVC) is well-suited for longitudinal evaluation of glymphatic system function and can potentially be integrated with cognitive or motor skill testing.