Targeted photothrombotic stroke leads to disruptions in neurovascular coupling

Abstract

Functional neuroimaging, which measures hemodynamic responses to brain activity, has great potential for monitoring stroke patients. However, the neurophysiological interpretations of these hemodynamic signals remain a challenge as the stroke is likely to alter both neural activity and neurovascular coupling. To address this challenge, we simultaneously captured neural activity, through fluorescence calcium imaging, and hemodynamics, through intrinsic optical signal imaging, during longitudinal stroke recovery. We found that photothrombotic stroke to somatosensory forelimb region altered neurovascular coupling in the acute phase (2 days and 1 week post-stroke) within the affected forelimb and peri-infarct regions. Neurovascular coupling was reestablished in the chronic phase (4 weeks post-stroke), and acute recovery of neurovascular coupling predicted sensorimotor function. Stroke also resulted in increases in the power of global brain oscillations, which showed distinct patterns between calcium and hemodynamics. Increased calcium excitability in the contralesional hemisphere was associated with increased intrahemispheric connectivity. Additionally, acute increases in hemodynamic oscillations were associated with improved sensorimotor outcomes. TeaserAcute ischemic stroke leads to neurovascular uncoupling and the extent of early recoupling predicts sensorimotor recovery.