High incidence of adverse cerebral blood flow responses to spreading depolarization in the aged ischemic rat brain.
Spreading depolarizations (SDs) occur spontaneously in the brain after stroke, exacerbate ischemic injury, and thus emerge as a potential target of intervention. Aging predicts worse outcome from stroke; yet, the impact of age on SD evolution is not clear. Cerebral ischemia was induced by bilateral common carotid artery occlusion in young (8-9 weeks old, n = 8) and old (2 year olds, n = 6) anesthetized rats. Sham-operated animals of both age groups served as control (n = 12). Electrocorticogram, direct current potential, and cerebral blood flow (CBF) variations were acquired via a small craniotomy above the parietal cortex. SDs were elicited by KCl through a second craniotomy distal to the recording site. Ischemia and age delayed the recovery from SD. CBF decreased progressively during ischemia in the old animals selectively, and inverse neurovascular coupling with SD evolved in the old but not in the young ischemic group. We propose that (mal)adaptation of cerebrovascular function with aging impairs the SD-related CBF response, which is implicated in the intensified expansion of ischemic damage in the old brain.
Department of Medical Physics and Informatics, Faculty of Medicine, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
Ákos
Á
Menyhárt
Department of Medical Physics and Informatics, Faculty of Medicine, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
Péter
P
Makra
Department of Medical Physics and Informatics, Faculty of Medicine, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
Borbála É
BÉ
Szepes
Department of Medical Physics and Informatics, Faculty of Medicine, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
Orsolya M
OM
Tóth
Department of Medical Physics and Informatics, Faculty of Medicine, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
Péter
P
Hertelendy
Department of Medical Physics and Informatics, Faculty of Medicine, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
Ferenc
F
Bari
Department of Medical Physics and Informatics, Faculty of Medicine, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary. Electronic address: farkas.eszter.1@med.u-szeged.hu.
Eszter
E
Farkas
D000375:Aging / Q000473:pathology* / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000473:pathology*; D002545:Brain Ischemia / Q000473:pathology* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D000069280:Electrocorticography; D008297:Male; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar
Aging; Cerebral blood flow; Cerebral ischemia; Electrophysiology; Rat; Spreading depolarization