Fig. 3: Experimental procedure for evaluation of mTBI in ALDH2−/− mouse model using behavioural tests, histology, and ProxyNA3 CEST-MRI.
From: Aldehydic load as an objective imaging biomarker of mild traumatic brain injury
A Chemical structure of ProxyNA3 in its unbound, silent state (left), and its CEST-MRI active state, upon reaction with aldehyde (right). B Western blots showing protein levels of ALDH2 in the liver (top) and brain (bottom) tissues from transgenic mice with ALDH2 +/+, +/−, and −/− genotypes. Vinculin was used as a loading control protein. C Experimental design for all testing done pre- and post-impact for in vivo mouse model of mTBI. CEST-MRI with ProxyNA3 was performed pre- and at two- and seven days post-impact. Behavioural tests, denoted by grid-walk symbol, was performed pre- and immediately post-impact. A separate cohort of mice were used for immunohistological examination at the same timepoints as MRI. D Results of neurological severity score (NSS) comprised of 5 pass-or-fail tests pre-impact (black) and post-impact (red). A point was awarded for every test failed, with a score of 5 representing the most severe behavioural deficit. E, F Immediately after NSS test, mice were placed on a raised grid with video recording for 3 min. A researcher blindly scored (E) the fraction of time spent active and (F) the total number of foot faults divided by total number of forelimb steps. Groups of mice were chosen by age (young <16 weeks; aged >65 weeks) and by genotype. Individual data points (n = 4 per group) and box plots are shown. *p < 0.05, 2-way ANOVA followed by Tukey-corrected multiple comparisons test.
