title: Mechanical difference between white and gray matter in the rat cerebellum measured by scanning force microscopy.
abstract: The mechanical properties of tissues are increasingly recognized as important cues for cell physiology and pathology. Nevertheless, there is a sparsity of quantitative, high-resolution data on mechanical properties of specific tissues. This is especially true for the central nervous system (CNS), which poses particular difficulties in terms of preparation and measurement. We have prepared thin slices of brain tissue suited for indentation measurements on the micrometer scale in a near-native state. Using a scanning force microscope with a spherical indenter of radius ∼20μm we have mapped the effective elastic modulus of rat cerebellum with a spatial resolution of 100μm. We found significant differences between white and gray matter, having effective elastic moduli of K=294±74 and 454±53Pa, respectively, at 3μm indentation depth (n(g)=245, n(w)=150 in four animals, p<0.05; errors are SD). In contrast to many other measurements on larger length scales, our results were constant for indentation depths of 2-4μm indicating a regime of linear effective elastic modulus. These data, assessed with a direct mechanical measurement, provide reliable high-resolution information and serve as a quantitative basis for further neuromechanical investigations on the mechanical properties of developing, adult and damaged CNS tissue.
authors.affiliation: Cavendish Laboratory, Department of Physics, University of Cambridge, 19 J.J. Thomson Avenue, Cambridge CB3 0HE, UK.
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Christ
authors.forename: Kristian
authors.initials: K
authors.lastname: Franze
authors.forename: Helene
authors.initials: H
authors.lastname: Gautier
authors.forename: Pouria
authors.initials: P
authors.lastname: Moshayedi
authors.forename: James
authors.initials: J
authors.lastname: Fawcett
authors.forename: Robin J M
authors.initials: RJ
authors.lastname: Franklin
authors.forename: Ragnhildur T
authors.initials: RT
authors.lastname: Karadottir
authors.forename: Jochen
authors.initials: J
authors.lastname: Guck
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002531:Cerebellum / Q000033:anatomy & histology / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology; D005260:Female; D018625:Microscopy, Atomic Force / Q000379:methods*; D008959:Models, Neurological; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical