The obvious notion has been that blood vessels in the brain are only involved in the transportation of nutrients and oxygen to nourish the organ, and that’s all.
However, recent findings reveal they do more, these blood vessels also instruct brain development.
A new study by Goethe University Frankfurt, researchers looked into how neural vascular networks develop at different stages, and their report is that brain blood vessels have a novel function: they are at the center in orchestrating the proper growth of neural cellular networks in the brain.
Brain Function and Homeostasis
It is estimated that the brain has over 100 billion neural networks, each tasked with various interdepended functions. This makes it the most complex organ in the human body — and as such, a lot of metabolic equilibrium, what scientists call homeostasis needs to be maintained for growth and optimal function of the organ.
Homeostasis and function of the brain depend on communication between the multifaceted network of cells that make the organ.
“Now, for that to be achieved the development of various groups of cells in the brain need to be synchronized on time and in space, and blood vessels happen to be at the center to ensure that,” states the report by Goethe University and the Acker-Palmer group, which also appears in the recent issue of journal Science.
Why this Matters
In other words, blood vessels ensure neural cellular networks in the brain develop fittingly for proper function.
This study, which looks into the signaling pathways and mechanisms that takes place between these two systems, promises to offer fundamental approaches for treating neural degenerative related conditions such as dementia and other mental illnesses.
Vascularization of the brain (the organic process where body tissues turn to become vascular and develop capillaries) is necessary for bringing forth neurons and glial cells. Proper supply of nutrients and oxygen is key as these support metabolic functions in neuronal networks.
The Study in a Glimpse
“We knew by intuition that both the nervous system and the vascular system function are dependent on each other, and similar vocabularies could be used to explain how these systems synchronize and communicate to facilitate proper brain function, but now we can prove this, explained Acker-Palmer.
Analyzing communication of neuronal cells and blood vessels, the Acker-Palmer group agreed to investigate different aspects of neurovascular development. So they used a well-established technique to investigate molecules that are key in vascular growth: in this case vascularization of the mouse retina.
With this approach they found out that a molecule by the name Reelin (which initially proved to influence neural migrations) happen to independently influence the development of vessels by deploying a very similar signaling mechanism: they activated the Dab1 protein and ApoER2 receptor expressed in endothelial cells.
The Cerebral Cortex
The cerebral cortex is another key structure in basic brain functions. It plays a significant role in language perception, attention, consciousness, and memory. Right from embryonic development, in the cerebral cortex, neuronal cells need to be organized in layers.
As such, the scientists excluded Reelin signaling cascade from endothelial cells to see what happens, how this could influence the arrangement of glial cells and neurons in the cerebral cortex.
The astonishing finding was that, even with exclusion of the Reelin signaling cascade, endothelial cells instructed neurons regarding their exact correct positioning in the cerebral cortex.