Could cerebrospinal fluid interactions in the brain help us understand neurodevelopmental conditions?

Researchers have demonstrated novel cerebrospinal fluid dynamics in the brain, which could hold promise for the future of neurodevelopmental research.

A recent study at Washington University School of Medicine in St. Louis (MO, USA) has begun to uncover how cerebrospinal fluid (CSF) interacts with the brain, utilizing a new X-ray imaging technique to visualize fluid circulation. The study provides early research into the role of CSF and could have implications for a wide range of neurodevelopmental conditions, including hydrocephalus.

CSF cushions the brain against injury, supplies it with nutrients and carries away waste; but has the role that CSF plays in brain development and function been underestimated? Research has generally focused on CSF drainage, with a lack of studies investigating its interface with the brain.

The researchers developed a novel X-ray microtomography imaging technique using gold nanoparticles, which allowed them to track the circulation of CSF. They then used the technique to track CSF in young rodents and identified alternate pathways for CSF drainage. Furthermore, they found that the fluid flows to specific functional areas – intraparenchymal cells – associated with anatomic brain structures that are still developing.

“Our next steps are to understand why cerebrospinal fluid is flowing to these neurons specifically and what molecules are being carried in the cerebrospinal fluid to those areas. There are growth factors within the cerebrospinal fluid that may be interacting with these specific neuronal populations to mediate development, and the interruption of those interactions could result in different disease pathways,” hypothesized corresponding author Jennifer Strahle.

Hydrocephalus, a disorder of excess fluid in the brain, can develop following bleeding in the brain in premature babies and can cause developmental delays. In further experiments, the team induced a hydrocephalus model in young rats and found that there were fewer channels transporting CSF from the outside to the middle of the brain. They also found that circulation to the functional areas was significantly reduced.

Disruptions to the movement of CSF to functional areas in the brain could be responsible for disease states. “In the setting of hydrocephalus, it’s common to see cognitive dysfunction that persists even after we successfully drain the excess fluid. The disordered cerebrospinal fluid dynamics to these functional regions of the brain may ultimately affect brain development, and normalizing flow to these areas is a potential approach to reducing developmental problems. It is an exciting field, and we are only at the beginning of understanding the diverse functions of cerebrospinal fluid,” concluded Strahle.