Spatiotemporal Dynamics of Perfusion and Oximetry during Ictal Discharges in the Rat Neocortex Export

@article{citeulike:4307058, abstract = {Epileptic events elicit a large focal increase in cerebral blood flow (CBF) to perfuse metabolically active neurons in the focus. Conflicting data exists, however, on whether hemoglobin saturation increases or decreases in the focus and surrounding cortex, and whether CBF increases globally or is decreased in adjacent areas. How these hemodynamic events correlate with actual changes in tissue oxygenation is also not known. Using laser Doppler flowmetry, oxygen microsensors and intrinsic optical imaging spectroscopy, we demonstrate that the dip in hemoglobin in the focus correlates with a profound but temporary decrease in tissue oxygenation despite a large increase in CBF. Furthermore, CBF simultaneously decreases in the cortex immediately adjacent to the focus. These events are then replaced with a longer duration, less focal increase in CBF, cerebral blood volume, and hyperoxygenation, the duration of which correlates with the duration of the seizure. These findings raise the question of whether transient focal hypoxia and vascular steal might contribute to progressive deleterious effects of chronic epilepsy on the adult and developing brain. Possible mechanisms based on recent astrocyte-based models of neurovascular coupling are discussed. 10.1523/JNEUROSCI.4667-08.2009}, author = {Zhao, Mingrui and Ma, Hongtao and Suh, Minah and Schwartz, Theodore H.}, citeulike-article-id = {4307058}, citeulike-linkout-0 = {http://dx.doi.org/10.1523/JNEUROSCI.4667-08.2009}, citeulike-linkout-1 = {http://www.jneurosci.org/cgi/content/abstract/29/9/2814}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/19261877}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=19261877}, day = {4}, doi = {10.1523/JNEUROSCI.4667-08.2009}, journal = {J. Neurosci.}, keywords = {epilepsy, intrinsic, optical, qual}, month = {March}, number = {9}, pages = {2814--2823}, posted-at = {2009-04-14 13:22:13}, priority = {2}, title = {Spatiotemporal Dynamics of Perfusion and Oximetry during Ictal Discharges in the Rat Neocortex}, url = {http://dx.doi.org/10.1523/JNEUROSCI.4667-08.2009}, volume = {29}, year = {2009} }

TY - JOUR ID - citeulike:4307058 L3 - citeulike-article-id:4307058 N2 - Epileptic events elicit a large focal increase in cerebral blood flow (CBF) to perfuse metabolically active neurons in the focus. Conflicting data exists, however, on whether hemoglobin saturation increases or decreases in the focus and surrounding cortex, and whether CBF increases globally or is decreased in adjacent areas. How these hemodynamic events correlate with actual changes in tissue oxygenation is also not known. Using laser Doppler flowmetry, oxygen microsensors and intrinsic optical imaging spectroscopy, we demonstrate that the dip in hemoglobin in the focus correlates with a profound but temporary decrease in tissue oxygenation despite a large increase in CBF. Furthermore, CBF simultaneously decreases in the cortex immediately adjacent to the focus. These events are then replaced with a longer duration, less focal increase in CBF, cerebral blood volume, and hyperoxygenation, the duration of which correlates with the duration of the seizure. These findings raise the question of whether transient focal hypoxia and vascular steal might contribute to progressive deleterious effects of chronic epilepsy on the adult and developing brain. Possible mechanisms based on recent astrocyte-based models of neurovascular coupling are discussed. 10.1523/JNEUROSCI.4667-08.2009 IS - 9 JF - J. Neurosci. EP - 2823 TI - Spatiotemporal Dynamics of Perfusion and Oximetry during Ictal Discharges in the Rat Neocortex VL - 29 SP - 2814 KW - epilepsy KW - intrinsic KW - optical KW - qual AU - Zhao, Mingrui AU - Ma, Hongtao AU - Suh, Minah AU - Schwartz, Theodore PY - 2009/03/04/ UR - http://dx.doi.org/10.1523/JNEUROSCI.4667-08.2009 ER -