Visualizing Clearance of Cerebrospinal Fluid via the Glymphatic System
Evidence strongly suggests that failing drainage of cerebrospinal fluid contributes to neurodegeneration, as the flow of fluid from the brain into the body carries metabolic waste with it. This metabolic waste, such as misfolded amyloid-β, becomes more prone to accumulate given the reduced drainage that occurs in later life, and this accumulation contributes to the onset and progression of neurodegenerative conditions. One of the pathways for drainage is the comparatively recently discovered glymphatic system. Here, researchers discuss a way to measure the flow of cerebrospinal fluid through the glymphatic system. Putting numbers to the problem of reduced drainage is an important step on the way to doing something about it.
Glymphatic clearance dysfunction may play an important role in a variety of neurodegenerative diseases and the progression of ageing. However, in vivo imaging of the glymphatic system is challenging. In this study, we describe an MRI method based on chemical exchange saturation transfer (CEST) of the Angiopep-2 probe to visualize the clearance function of the glymphatic system.
We injected rats with Angiopep-2 via the tail vein and performed in vivo MRI at 7 T to track differences in Angiopep-2 signal changes; we then applied the same principles in a bilateral deep cervical lymph node ligation rat model and in ageing rats. We demonstrated the feasibility of Angiopep-2 CEST for visualizing the clearance function of the glymphatic system. Finally, a pathological assessment was performed. Within the model group, the deep cervical lymph node ligation group and the ageing group showed higher CEST signal than the control group. We conclude that this new MRI method can visualize clearance in the glymphatic system.
Is it true that if you sleep with your feet a bit higher than your head you'll drain more out via the glymphatic system?
https://molecularneurodegeneration.biomedcentral.com/articles/10.1186/s13024-023-00681-w
Blood platelet factor 4: the elixir of brain rejuvenation
José M. Izquierdo
Molecular Neurodegeneration volume 19, Article number: 3 (2024) Cite this article
356 Accesses
11 Altmetric
Metricsdetails
Aging is invariably associated with some form of cognitive impairment. Three recently published articles in Nature family journals from independent groups reported that the plasma levels of platelet factor four (PF4) are negatively associated with brain aging and neurodegeneration phenotypes and positively associated with cognitive performance, brain rejuvenation and health. These studies identify a humble blood-derived chemokine as a potential elixir of brain youth.
One of the three groups, led by Saul Villeda at the University of California at San Francisco (UCSF), had previously shown that administration of blood plasma from young mice rejuvenated the brains of old mice [1]. When they analyzed how young plasma differed from old plasma, they identified PF4 as the chemokine that transfers the restorative effects of young blood to aging brains [2]. Specifically, PF4 attenuated age-related neuroinflammation by rejuvenating the immune system, rescuing synaptic plasticity and improving hippocampal-dependent learning and memory in a partially CXCR3 chemokine receptor-dependent manner (Fig. 1). A second UCSF team led by Dena Dubal previously showed that klotho, a hormone linked to longevity, could improve cognition when administered to m