title: Combined two-photon laser-scanning microscopy and spectral microCT X-ray imaging to characterize the cellular signature and evolution of microstroke foci.
abstract: Occlusive brain ischemia and micro-strokes are the most frequent brain pathologies, particularly in older patients and a major cause of dementia. Currently, we are missing appropriate methodology to study micro-strokes in experimental animals. In vivo two-photon laser-scanning microscopy (2P-LSM) and transgenic mouse models expressing cell type specific reporters have been used to examine ischemia-related insults, e.g. perturbations of neuronal process morphology and local blood flow in the MCAO - middle cerebral artery occlusion-model. Glia and pericytes can be visualized by selective fluorescent protein expression, e.g. astrocytes by their cyan-fluorescent ECFP, pericytes by red-fluorescent tdtomato and microglia by green fluorescent EGFP expression. In these mice, the breakdown of the blood brain barrier and the immediate as well as long-term cellular responses can be monitored. A new prototype of microCT incorporating a fast X-ray XPAD3 camera has been recently set up to allow cerebral angiography at high sampling rate. Preliminary data indicate that it is useful to monitor blood perfusion disturbance (i.e. lateralization) in the brain of tumor-bearing mice following retro-orbital injection of iodinated contrast agent. We expect this technology to be adequate to assess in real time the impact of acute stroke models on brain blood perfusion. By localizing perfusion anomalies, we will evaluate the extent of non-perfused areas and correlate these observations with subsequent behavioral deficits, and with local changes in myelin content in white matter tracks. The spectral properties of the XPAD3 detector moreover allow for the simultaneous identification and localization of several contrast agents opening the way to whole body multicolor imaging of vessels and inflammatory cells in the context of microstrokes.
authors.affiliation: Department of Molecular Physiology, University of Saarland, Homburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Kirchhoff
authors.forename: F
authors.initials: F
authors.lastname: Debarbieux
authors.forename: Carine
authors.initials: C
authors.lastname: Kronland-Martinet
authors.forename: G R
authors.initials: GR
authors.lastname: Cojocaru
authors.forename: A
authors.initials: A
authors.lastname: Popa-Wagner
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D018613:Microscopy, Confocal / Q000379:methods*; D011859:Radiography; D020521:Stroke / Q000000981:diagnostic imaging / Q000473:pathology*