Laser speckle contrast imaging for blood flow monitoring in predicting outcomes after cerebral ischemia-reperfusion injury in mice

Abstract

Background In the treatment of ischemic cerebral stroke (ICS), most conventional treatments, including carotid endarterectomy and carotid artery stenting, may cause cerebral ischemia-reperfusion injury (CIRI). For treated ICS patients, changes in cerebral blood flow are directly related to brain function. At present, computed tomography perfusion, dynamic susceptibility contrast-enhanced perfusion weighted imaging and magnetic resonance arterial spin labeling perfusion imaging are used to monitor cerebral blood flow, but they still have some limitations. Our study aimed to monitor the changes in cerebral cortical blood flow by laser speckle contrast imaging (LSCI) in CIRI model mice and to propose a new method for predicting outcomes after CIRI. C57BL/6 N mice were used to establish a mouse CIRI model based on a modified thread-occlusion method and divided into a good outcome group and a poor outcome group according to survival within 7 days. The cerebral cortical blood flow of the area supplied by the left middle cerebral artery was monitored by LSCI at baseline (before modeling), 1 h after ischemia, immediately after reperfusion and 24 h after reperfusion. Then, the brains of the mice were removed immediately and stained with hematoxylin and eosin to observe the pathological changes in brain neurons. Results The cerebral cortical blood flow in the poor outcome group was obviously reduced compared with that less in the good outcome group at 24 h after reperfusion (180.8 ± 20.9 vs. 113.9 ± 6.4, p = 0.001), and at 24 h after reperfusion, the cerebral cortical blood flow was negatively correlated with the severity of brain tissue injury (p = − 0.710, p = 0.010). Conclusions LSCI can monitor the changes in cerebral cortical blood flow during CIRI in mice and could be used as a feasible method for predicting outcomes after CIRI in mice.

Astragaloside IV combined with ligustrazine ameliorates abnormal mitochondrial dynamics via Drp1 SUMO/deSUMOylation in cerebral ischemia–reperfusion injury

“… 43 Moreover, 24 h after cerebral I/R in rats, CBF in the cerebral cortex was found to be negatively correlated with the severity of brain tissue damage in a prior study. 44 This was consistent with the outcomes of our research. Meanwhile, AST IV, Lig, and AST IV combined with Lig were demonstrated to increase CBF and reduce brain infarct volume and tissue damage.…”

“…43 Moreover, 24 h after cerebral I/R in rats, CBF in the cerebral cortex was found to be negatively correlated with the severity of brain tissue damage in a prior study. 44 This was consistent with the outcomes of our re- in impaired mitochondrial membrane potential and ultimately aggravating tissue injury. 47 Prior studies found that AST IV 48,49 and Lig 30,31 could alleviate I/R-induced apoptosis by maintaining the mitochon- pathophysiological injury of damaged mitochondria on neurons.…”

“…CIRI is a complex pathological process involving various mechanisms, including inflammation, excitotoxicity of amino acids, calcium overload, energy metabolism disorders, and oxidative stress, directly or indirectly leading to cerebral infarction and the loss of neurological and cognitive function 43 . Moreover, 24 h after cerebral I/R in rats, CBF in the cerebral cortex was found to be negatively correlated with the severity of brain tissue damage in a prior study 44 . This was consistent with the outcomes of our research.…”

Pre-Hospital Stroke Care beyond the MSU

“…Preclinical studies showed that Laser speckle contrast imaging can be used to measure cerebral blood flow in mice [78]. Laser Speckle Contrast Imaging is a non-invasive optical method with high temporal and spatial resolution that relies on the phenomenon known as "laser speckle," which occurs when a laser beam illuminates a surface (such as tissue) and creates a random interference pattern.…”

Advances in Dynamic Light Scattering Imaging of Blood Flow

“…[172,173] With the further development of approach, the CBF changes caused by cerebral ischemia re-perfusion injury were monitored. [174] Besides, different approaches for assessment of CBF changes during activation in the somatosensory cortex by repetitive whisker stimulation have been analyzed. [175] It has been shown that principal component analysis (PCA) can significantly reduce the noise in speckle contrast data.…”