title: Advancing age and ischemia elevate the electric threshold to elicit spreading depolarization in the cerebral cortex of young adult rats.
abstract: Spreading depolarizations of long cumulative duration have been implicated in lesion development and progression in patients with stroke and traumatic brain injury. Spreading depolarizations evolve less likely in the aged brain, but it remains to be determined at what age the susceptibility to spreading depolarizations starts to decline, especially in ischemia. Spreading depolarizations were triggered by epidural electric stimulation prior and after ischemia induction in the cortex of 7-30 weeks old anesthetized rats ( n = 38). Cerebral ischemia was achieved by occlusion of both common carotid arteries. Spreading depolarization occurrence was confirmed by the acquisition of DC potential and electrocorticogram. Cerebral blood flow variations were recorded by laser-Doppler flowmetry. Dendritic spine density in the cortex was determined in Golgi-COX stained sections. Spreading depolarization initiation required increasingly greater electric charge with older age, a potential outcome of consolidation of cortical connections, indicated by altered dendritic spine distribution. The threshold of spreading depolarization elicitation increased with ischemia in all age groups, which may be caused by tissue acidosis and increased K+conductance, among other factors. In conclusion, the brain appears to be the most susceptible to spreading depolarizations at adolescent age; therefore, spreading depolarizations may occur in young patients of ischemic or traumatic brain injury at the highest probability.
authors.affiliation: 1 Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Hertelendy
authors.affiliation: 1 Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors.forename: Ákos
authors.initials: Á
authors.lastname: Menyhárt
authors.affiliation: 1 Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Makra
authors.affiliation: 2 Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Szeged, Szeged, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Süle
authors.affiliation: 1 Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Kiss
authors.affiliation: 1 Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: Tóth
authors.affiliation: 1 Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Ivánkovits-Kiss
authors.affiliation: 1 Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Bari
authors.affiliation: 1 Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors.forename: Eszter
authors.initials: E
authors.lastname: Farkas
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000375:Aging / Q000502:physiology*; D000818:Animals; D002545:Brain Ischemia / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000098:blood supply / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D013181:Cortical Spreading Depression / Q000502:physiology*; D049229:Dendritic Spines / Q000502:physiology; D004558:Electric Stimulation; D000069280:Electrocorticography; D017078:Laser-Doppler Flowmetry; D008297:Male; D017207:Rats, Sprague-Dawley
keywords: Age; cerebral blood flow; electrophysiology; spreading depolarization; threshold