title: Dynamic spatio-temporal imaging of early reflow in a neonatal rat stroke model.
abstract: The aim of the study was to better understand blood-flow changes in large arteries and microvessels during the first 15 minutes of reflow in a P7 rat model of arterial occlusion. Blood-flow changes were monitored by using ultrasound imaging with sequential Doppler recordings in internal carotid arteries (ICAs) and basilar trunk. Relative cerebral blood flow (rCBF) changes were obtained by using laser speckle Doppler monitoring. Tissue perfusion was measured with [(14)C]-iodoantipyrine autoradiography. Cerebral energy metabolism was evaluated by mitochondrial oxygen consumption. Gradual increase in mean blood-flow velocities illustrated a gradual perfusion during early reflow in both ICAs. On ischemia, the middle cerebral artery (MCA) territory presented a residual perfusion, whereas the caudal territory remained normally perfused. On reflow, speckle images showed a caudorostral propagation of reperfusion through anastomotic connections, and a reduced perfusion in the MCA territory. Autoradiography highlighted the caudorostral gradient, and persistent perfusion in ventral and medial regions. These blood-flow changes were accompanied by mitochondrial respiration impairment in the ipsilateral cortex. Collectively, these data indicate the presence of a primary collateral pathway through the circle of Willis, providing an immediate diversion of blood flow toward ischemic regions, and secondary efficient cortical anastomoses in the immature rat brain.
authors.affiliation: Sorbonne Paris Cité, INSERM U676, Univ Paris Diderot, Paris, France.
authors.forename: Pierre-Louis
authors.initials: PL
authors.lastname: Leger
authors.forename: Philippe
authors.initials: P
authors.lastname: Bonnin
authors.forename: Pierre
authors.initials: P
authors.lastname: Lacombe
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Couture-Lepetit
authors.forename: Sebastien
authors.initials: S
authors.lastname: Fau
authors.forename: Sylvain
authors.initials: S
authors.lastname: Renolleau
authors.forename: Abdallah
authors.initials: A
authors.lastname: Gharib
authors.forename: Olivier
authors.initials: O
authors.lastname: Baud
authors.forename: Christiane
authors.initials: C
authors.lastname: Charriaut-Marlangue
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001345:Autoradiography; D001783:Blood Flow Velocity / Q000502:physiology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000254:growth & development / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004195:Disease Models, Animal; D017078:Laser-Doppler Flowmetry; D008279:Magnetic Resonance Imaging; D055806:Microvessels / Q000000981:diagnostic imaging / Q000254:growth & development / Q000503:physiopathology*; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000254:growth & development / Q000503:physiopathology*; D008928:Mitochondria / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D062211:Spatio-Temporal Analysis; D020521:Stroke / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D014463:Ultrasonography