Fig. 7. Protein Changes Induced by Mutlple Stretch-injuries in BrainPhys®/SM1+Matrigel Maintained Cultures.

DIV9 cortical neurons were given a single or multiple 54% biaxial stretch-injuries, and cell culture media plus protein extracts were harvested 24h later (n=3/group). (a) Diagram showing a time course of experimental injury variables. T0 = 1^st injury which is denoted as time zero. T1h = a 2^nd injury adminstered at 1h after the first injury. T4h = a 2^nd injury adminstered at 4h after the first injury. T8h = a 2^nd injury adminstered at 8h after the first injury. Samples were collected 24h from the start of T0 in all groups. (b) LDH levels were significantly higher in cultures given a single 54% stretch-injury versus uninjured controls. LDH levels were further augmented by multiple stretch-injuries. (c) Representative total membrane stain shows equal protein loading/transfer of samples across groups. (d) Westerm blots show the effect of stretch-injury on αII-Spectrin breakdown products (SBDPs), NFL, Tau, and Tubulin. (e–g) Densitometric analysis of SBDPs, NF-L, and Tau, respectively (n=3/group). Data were anlayzed by 1-WAY-ANOVA followed by Newman-Keuls post-hoc. Data were significant at p<.05. (a) = a significant post-hoc difference comparing injury group versus uninjured control. (b) = a significant post-hoc difference comparing the single stretch-injury group (T0 only) versus a multiple stretch-injury group. Graphs show mean +SEM.