Imaging the Impact of Cortical Microcirculation on Synaptic Structure and Sensory-Evoked Hemodynamic Responses In Vivo
2007

Impact of Blood Flow on Brain Structure and Function After Stroke

Sample size: 19 publication 10 minutes Evidence: high

Author Information

Author(s): Zhang Shengxiang, Murphy Timothy H

Primary Institution: University of British Columbia

Hypothesis

How does cortical microcirculation affect synaptic structure and hemodynamic responses in the brain during and after a stroke?

Conclusion

The study shows that intact dendritic structure can be maintained by blood flow from vessels up to 80 μm away, while brain function is more sensitive to blood flow interruptions.

Supporting Evidence

  • Intact dendritic structure can be maintained by blood flow from vessels that are on average 80 μm away.
  • Functional imaging indicated that sensory-induced changes in signal were blocked in areas with damaged dendrites.
  • Acute ischemic damage to dendrites was triggered within 30 min when blood flow over >0.2 mm2 of cortical surface was blocked.
  • Normal synaptic structure can be maintained in ischemic areas if nearby blood flow is present.
  • Sharp transitions between intact and damaged synaptic circuitry were observed over tens of micrometers.

Takeaway

When blood flow to the brain is blocked, some parts of the brain can still work normally if they are close enough to healthy blood vessels.

Methodology

In vivo two-photon microscopy was used to image dendrites and their spines in a mouse stroke model, assessing the relationship between blood flow and synaptic structure.

Potential Biases

Potential bias due to the specific model used, which may not reflect all aspects of human stroke.

Limitations

The RB photothrombosis model may not fully replicate the histopathology observed in clinical stroke scenarios.

Participant Demographics

Adult, urethane-anesthetized C57BL/6 YFP-H or GFP-M expressing transgenic mice aged 2–5 months.

Statistical Information

P-Value

p<0.05

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pbio.0050119

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