Axonal Beading and Microtubule Quantification
Purpose: Focal axonal beading and focal disruption of microtubule structure are characteristic to traumatic axonal injury. We reproduced these morphological and structural changes in our in vitro model system [Kilinc, Gallo, Barbee, 2008. Exp. Neurol. 212:422–430]. In order to measure bead formation objectively, an observer-independent quantification of beading was necessary. In addition, a quantitative measure for the extent of co-localization of axonal beads and microtubule disruptions was required to establish a causal relationship between focal cytoskeletal damage and bead formation. In this paper we describe Matlab-based, interactive image analysis programs for axonal beading quantification and co-localization analysis. Injury-induced increases in the axonal beading could be successfully detected using the bead analysis program.