Ask a Neuroscientist: Sarah Heilbronner

Why It Matters

Understanding brain structure, function, and connectivity via MRI enables early detection of neurological disorders and guides personalized therapeutic strategies.

Key Takeaways

• MRI provides structural, functional, and connectivity brain information.
• Structural MRI maps gray matter, white matter, ventricles, and skull.
• Functional MRI tracks brain activity during tasks like puzzles.
• Diffusion-weighted MRI infers axon direction via water molecule movement.
• Diffusion MRI is currently only way to approximate living brain wiring.

Summary

Dr. Sarah Heilbronner outlines how magnetic resonance imaging, the workhorse of modern neuroscience, can be tuned to reveal three distinct layers of brain information. Structural MRI produces high‑resolution maps of gray‑matter regions, white‑matter tracts, ventricles, and the brain’s relationship to the skull, highlighting individual anatomical variability. Functional MRI captures moment‑to‑moment neuronal activation by having subjects perform tasks—such as solving a crossword puzzle—while the scanner records localized blood‑oxygen changes that “light up” engaged regions. Diffusion‑weighted MRI leverages the random motion of water molecules; in tightly packed axon bundles, diffusion is constrained, allowing researchers to infer the orientation of fiber pathways and approximate the brain’s wiring diagram. These techniques together provide the only non‑invasive window into the living human connectome, informing both basic research and clinical diagnostics.

Original Description

How can we see inside the brain? Learn how different magnetic resonance imaging (MRI) techniques are used to build and help us visualize wiring diagrams of the brain. #AskaNeuroscientist