Neural Navigation: Advanced Computer Models Map Brain's Tiny Blood Vessels

Understanding how blood flows through the brain's smallest vessels is essential for unraveling neurological conditions such as stroke, Alzheimer's disease, and traumatic injuries. Traditional methods have struggled to capture the complex dynamics of these microvessels, including transitional vessels like penetrating arterioles and capillary sphincters, which play crucial roles in regulating brain blood flow.

Researchers from Florida Atlantic University’s College of Engineering and the FAU Sensing Institute (I-SENSE) have developed a detailed computational model simulating the brain's vasculature. This model represents each vessel segment as an adjustable valve, allowing scientists to study how blood moves and how vessels actively respond to changes in flow and pressure—a process known as vasodynamics.

The model integrates hemodynamics, the movement of blood, with vasodynamics to explore how vascular components work together to maintain stable cerebral blood flow amid fluctuations such as blood pressure changes or localized brain activity increases. Validation against biological data affirms the model's predictive accuracy.

Published in PLOS ONE, the study reveals four distinct phases of vessel operation based on blood pressure. At very low pressures, blood flow is insufficient, but as pressure increases, vessels enter a 'sweet spot' with steady flow. Beyond a critical point, vessels lose control, and blood flow surges, risking vessel damage.

Senior author Dr. Ramin Pashaie explains that transitional vessels are particularly vital—they make significant adjustments to ensure consistent oxygen and nutrient supply, especially under varying physiological conditions. The endothelial cells lining the vessels can only constrict so much before control over blood flow diminishes, potentially stressing vessel walls and contributing to disease.

The model also captures how blood flow responds during brain activity, increasing—known as functional hyperemia—differently across vessel types and locations. In outer brain layers, sphincters primarily regulate this flow, while deeper regions rely on penetrating arterioles.

This research advances understanding of microvascular regulation, offering insights for early diagnosis of neurological disorders. Tied to ongoing work in early Alzheimer’s detection, the team hypothesizes that changes in microvascular blood flow regulation—detectable in the retina—could serve as non-invasive biomarkers for early disease stages. By integrating biological and computational approaches, these findings pave the way for improved diagnostics, treatments, and understanding of brain health.

The study exemplifies the power of interdisciplinary collaboration and innovative modeling in neuroscience, with future plans to refine the model further and eventually adapt it for human brain analysis.