Arterial specification precedes microvascular restitution in the peri-infarct cortex that is driven by small...

Area of Science:

• Neuroscience
• Vascular Biology
• Medical Imaging

Background:

• Assessing 3D microvascular networks post-stroke was challenging due to tissue sectioning limitations.
• Understanding microvascular remodeling is crucial for developing effective stroke treatments.

Purpose of the Study:

• To investigate long-term microvascular network alterations in the mouse peri-infarct cortex after ischemic stroke.
• To evaluate the impact of FTY720 (Fingolimod) on microvascular changes post-stroke.
• To demonstrate the utility of light-sheet microscopy and AI for analyzing microvascular architecture.

Main Methods:

• Light-sheet microscopy was employed to image the peri-infarct cortex in mice over 56 days post-stroke.
• Transient middle cerebral artery occlusion (tMCAO) was used to induce ischemic stroke.
• An AI-based algorithm analyzed microvessel length density, branching points, and expression of α-smooth muscle actin.

Main Results:

• A transient loss and subsequent reappearance of microvessels were observed in the peri-infarct cortex.
• Increased microvessel length density and branching points, especially in small vessels, were noted from 7 to 56 days post-stroke.
• FTY720 administration enhanced the length and branch density of small microvessels.

Conclusions:

• Stroke induces significant long-term alterations in peri-infarct microvascular architecture, suggesting increased collateralization.
• Small microvessels play a key role in post-stroke recovery and collateralization.
• Light-sheet microscopy and AI analysis are powerful tools for assessing microvascular responses to stroke and potential therapies.