Synopsis

Vessel Dilation Controls Metabolite Flow in the Brain

Physics 12, s136
A new model predicts that the network pattern formed by the brain’s blood vessels plays no role in local metabolite transport, finding instead that vessel dilation is the key.

The brain’s tiny blood vessels form an intricate web-like network that transports metabolites and other substances including nutrients and hormones. But does the network’s specific pattern affect how it performs this vital role? Karen Alim of the Technical University of Munich and colleagues set out to answer this question by developing a theoretical model of the flow of metabolites in a brain-like network. They find that the network’s specific architecture does not matter when it comes to locally varying the supply of metabolites in the brain. Rather, vessel dilation acts as the metabolite “control knob.”

The researchers based their network on the vessel pattern of a rat’s brain. Then they studied how parameters such as the blood’s flow velocity and the metabolite’s uptake rate through the vessel walls governed the transfer of molecules from an individual vessel into the surrounding tissue. The team found that optimal transfer of metabolites occurs when the process is governed by advection. In this regime, when blood flow increases—something that happens when a blood vessel dilates—so too does metabolite transfer, with a 10% dilation leading to a 10% growth in metabolite supply. But surprisingly, Alim says, they found that the local network architecture around a given vessel played no role in increasing metabolite supply along that vessel: all that mattered was by how much the vessel itself dilated.

Changes in blood flow are used as a proxy for neural activity in brain imaging techniques like functional magnetic resonance imaging. Alim says that their model provides a tool to better quantify this process and potentially link the dilation of a single vessel to a spike in local brain activity.

This research is published in Physical Review Letters.

–Katherine Wright

Katherine Wright is a Senior Editor for Physics.


Subject Areas

Biological PhysicsFluid Dynamics

Related Articles

Shock Waves from Ions Damage DNA
Biological Physics

Shock Waves from Ions Damage DNA

Simulations show that the mechanical force of shock waves propagating through cells may be a key component of ion radiation damage to DNA.     Read More »

Altering Airflows and Stopping Drops
Fluid Dynamics

Altering Airflows and Stopping Drops

Two new studies provide insights into the efficacy of masks under different usage conditions, results that could help improve strategies for lowering transmission of COVID-19. Read More »

Bouncing Droplets Reveal New Leidenfrost Effect
Fluid Dynamics

Bouncing Droplets Reveal New Leidenfrost Effect

Droplets floating on vapor cushions can bounce off each other when they are composed of different liquids. Read More »

More Articles