title: A novel approach for mechanical tissue characterization indicates decreased elastic strength in brain areas affected by experimental thromboembolic stroke.
abstract: As treatment of ischemic stroke remains a challenge with respect to the failure of numerous neuroprotective attempts, there is an ongoing need for better understanding of pathophysiological mechanisms causing tissue damage. Although ischemic outcomes have been studied extensively at the cellular and molecular level using histological and biochemical methods, properties of ischemia-affected brain tissue with respect to mechanical integrity have not been addressed so far. As a novel approach, this study used fluorescence-based detection of regions affected by experimental thromboembolic stroke in combination with scanning force microscopy to examine mechanical alterations in selected rat brain areas. Twenty-five hours after onset of ischemia, a decreased elastic strength in the striatum as the region primarily affected by ischemia was found compared with the contralateral nonaffected hemisphere. Additional intrahemispheric analyses showed decreased elastic strength in the ischemic border zone compared with the more severely affected striatum. In conclusion, these data strongly indicate a critical alteration in mechanical tissue integrity caused by focal cerebral ischemia. Further, on the basis of data that have been obtained in relation to the ischemic border zone, a shell-like pattern of mechanical tissue damage was found in good accordance with the penumbra concept. These findings might enable the development of specific therapeutic interventions to protect affected areas from critical loss of mechanical integrity.
authors.affiliation: aDepartment of Neurology bPaul Flechsig Institute for Brain Research cInstitute of Anatomy dSection of Soft Matter Physics, Faculty of Physics and Geosciences, University of Leipzig, Leipzig, Germany eInterdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark.
authors.forename: Dominik
authors.initials: D
authors.lastname: Michalski
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Härtig
authors.forename: Martin
authors.initials: M
authors.lastname: Krueger
authors.forename: Carsten
authors.initials: C
authors.lastname: Hobohm
authors.forename: Josef A
authors.initials: JA
authors.lastname: Käs
authors.forename: Thomas
authors.initials: T
authors.lastname: Fuhs
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D000066670:Cell Plasticity / Q000502:physiology*; D003342:Corpus Striatum / Q000503:physiopathology; D004195:Disease Models, Animal; D008297:Male; D018625:Microscopy, Atomic Force; D051381:Rats; D017208:Rats, Wistar; D020521:Stroke / Q000209:etiology / Q000473:pathology*; D013923:Thromboembolism / Q000150:complications