“…A limitation of all previous work, including ours, is the application of hCSF obtained from unhealthy individuals. For instance, pooled CSF samples obtained from hydrocephalus patients were used as ''control'' CSF in all previous works (Buddensiek et al, 2009(Buddensiek et al, , 2010Gortz et al, 2013;Jantzen et al, 2013;Koch et al, 2019;Otto et al, 2009;Schwarz et al, 2017;Wickham et al, 2020). It has been known for decades that the chemical composition of hydrocephalus CSF differs from healthy CSF (e.g., Del Bigio, 1989), which indicates that these CSF samples might not be suitable to create a healthy, adult brain-like milieu in vitro.…”