Dynamic structural connectivity changes in cortical and cortico-striatal strokes in mice

Area of Science:

• Neuroscience
• Neuroimaging
• Stroke Research

Background:

• Stroke causes widespread brain alterations beyond initial damage.
• The impact of stroke lesion size and location on white matter changes and plasticity is not fully understood.

Purpose of the Study:

• To investigate how different stroke models (lesion size and topology) affect white matter changes over time.
• To compare structural connectivity dynamics in response to varying stroke severities.

Main Methods:

• Utilized repetitive diffusion magnetic resonance imaging in mice over 4 weeks post-stroke.
• Compared photothrombotic cortical (small) and middle cerebral artery occlusion (large) stroke models.
• Quantified whole-brain structural connectivity changes, including inter- and intra-hemispheric seed strength.

Main Results:

• Large cortico-striatal lesions increased structural connectivity in sensorimotor areas.
• Small cortical lesions resulted in asymmetric connectivity changes: increased from the ischemic hemisphere and decreased from the healthy hemisphere.
• Stroke severity and lesion size significantly influenced the timing and spatial patterns of connectivity disruptions.

Conclusions:

• Stroke-induced white matter alterations are dependent on lesion characteristics.
• Findings emphasize the need for monitoring neural changes tailored to stroke severity and lesion profile.
• This study provides insights into the brain's structural response to stroke, informing recovery and rehabilitation strategies.