title: Distinct vascular conduction with cortical spreading depression.
abstract: Cortical spreading depression (CSD) is associated with significant vasodilatation and vasoconstriction, but the relationship between the cortical parenchymal and vascular phenomena remains poorly understood. We used optical intrinsic signal (OIS) imaging and electrophysiology to simultaneously examine the vascular and parenchymal changes that occur with CSD in anesthetized mice and rats. CSD was associated with a propagated multiphasic change in optical reflectance, with correlated negative DC shift in field potential. Dilatation of cortical surface arterioles propagated with a significantly greater intrinsic velocity than the parenchymal CSD wavefront measured by OIS and electrophysiology. Dilatation traveled in a circuitous pattern along individual arterioles, indicating specific vascular conduction as opposed to concentric propagation of a parenchymal signal. Arteriolar dilatation propagated into areas beyond the spread of parenchymal OIS and electrophysiological changes of CSD. Conversely, vasomotor activity could be experimentally dissociated from the parenchymal CSD wave. Frequent repetitive CSD evoked by continuous stimulation was associated with a reduced or absent arteriolar response despite preserved parenchymal OIS and electrophysiological changes. Similarly, dimethylsulfoxide at high concentrations (10%) inhibited arteriolar reactivity despite preserved parenchymal OIS and electrophysiological changes. These results suggest a mechanism, intrinsic to the vasculature, for propagation of vasodilatation associated with CSD. Distinct vascular conduction could be important for the pathogenesis of conditions that involve CSD, including migraine, stroke, and traumatic brain injury.
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, Neurocience Research Building, Room 575, 635 Charles E. Young Drive South, Los Angeles, CA 90095, USA.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Brennan
authors.forename: Luis
authors.initials: L
authors.lastname: Beltrán-Parrazal
authors.forename: Hector E
authors.initials: HE
authors.lastname: López-Valdés
authors.forename: Jeremy
authors.initials: J
authors.lastname: Theriot
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Toga
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Charles
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000494:pharmacology; D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000502:physiology*; D002540:Cerebral Cortex / Q000098:blood supply / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D013181:Cortical Spreading Depression / Q000502:physiology*; D003952:Diagnostic Imaging / Q000379:methods; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004569:Electroencephalography; D007091:Image Processing, Computer-Assisted; D051379:Mice; D008810:Mice, Inbred C57BL; D010841:Pia Mater / Q000098:blood supply / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014661:Vasoconstriction; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
chemical_list: D018712:Analgesics, Non-Narcotic; D004121:Dimethyl Sulfoxide