Optical measurement of microvascular oxygenation and blood flow responses in awake mouse cortex during functional activation.
Ikbal Şencan-EğilmezTatiana EsipovaKıvılcım KılıçBaoqiang LiMichèle DesjardinsMohammad A YaseenHui WangJason E PorterSreekanth KuraBuyin FuTimothy W SecombDavid A BoasSergei A VinogradovAnna DevorSava SakadžićPublished in: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism (2020)
The cerebral cortex has a number of conserved morphological and functional characteristics across brain regions and species. Among them, the laminar differences in microvascular density and mitochondrial cytochrome c oxidase staining suggest potential laminar variability in the baseline O2 metabolism and/or laminar variability in both O2 demand and hemodynamic response. Here, we investigate the laminar profile of stimulus-induced intravascular partial pressure of O2 (pO2) transients to stimulus-induced neuronal activation in fully awake mice using two-photon phosphorescence lifetime microscopy. Our results demonstrate that stimulus-induced changes in intravascular pO2 are conserved across cortical layers I-IV, suggesting a tightly controlled neurovascular response to provide adequate O2 supply across cortical depth. In addition, we observed a larger change in venular O2 saturation (ΔsO2) compared to arterioles, a gradual increase in venular ΔsO2 response towards the cortical surface, and absence of the intravascular "initial dip" previously reported under anesthesia. This study paves the way for quantification of layer-specific cerebral O2 metabolic responses, facilitating investigation of brain energetics in health and disease and informed interpretation of laminar blood oxygen level dependent functional magnetic resonance imaging signals.
Keyphrases
- blood flow
- cerebral ischemia
- magnetic resonance imaging
- coronary artery
- resting state
- functional connectivity
- high glucose
- subarachnoid hemorrhage
- diabetic rats
- public health
- high resolution
- optical coherence tomography
- transcription factor
- healthcare
- high speed
- computed tomography
- mental health
- drug induced
- risk assessment
- metabolic syndrome
- deep brain stimulation
- room temperature
- single molecule
- endothelial cells
- high throughput
- multiple sclerosis
- human health
- adipose tissue
- type diabetes
- visible light
- insulin resistance
- contrast enhanced
- stress induced
- cerebral blood flow
- solar cells