Partial MHC/Neuroantigen Peptide Constructs: A Potential Neuroimmune-Based Treatment for Methamphetamine Addiction
Figure 2
Efficacy of RTL551 over vehicle in the treatment of methamphetamine induced spatial learning and memory impairments (n = 13–14 per group).
(a) Training sessions: time spent finding the visible and hidden platforms. Statistical analyses revealed no significant treatment group differences across study groups in terms of the latency to find the platform during the visible platform training sessions [Days 1 and 2; p = 0.39 (Gaussian approximation)]. This demonstrated that the groups were not significantly different in terms of basic motor function and perceptual abilities after treatment. Similar analyses also revealed no significant differences across treatment groups in terms of latency to find the platform during the hidden platform sessions [Days 3–5; p = 0.39 (Gaussian approximation)], suggesting that all groups were able to learn the task. (b) Memory test: Quadrant preference during the Day 5 probe trial (3rd day of hidden platform training). Statistical analyses revealed significant differences between the target and the three non-target quadrants for the following treatment groups: 1) Sal+Veh: Target versus Quadrants 1 (p<0.001), 2 (p<0.01) and 3 (p<0.05), 2) Meth+Veh: Target versus Quadrant 1 (p<0.001), 3) Sal+RTL551: Target versus Quadrants 1 (p<0.05), 2 (p<0.01), and 3 (p<0.01), 4) Meth+RTL551: Target versus Quadrants 1 (p<0.001), 2 (p<0.01) and 3 (p<0.05). In the Meth+Veh group, the percent time spent in each of the quadrants was only statistically different between quadrant 1 and the target quadrant, indicating that methamphetamine had induced significant memory impairments in this group. However, in the Meth+RTL551 group, mice spent significantly more time in the target quadrant than in all three of the other quadrants, indicating that RTL had significantly attenuated the methamphetamine induced spatial memory impairments in this group. The inset graph illustrates the differences in preference for the target quadrant across all treatment groups. When comparing all treatment groups, there was not a statistically significant difference in preference for the target quadrant [Kruskal-Wallis test, p = 0.27 (Gaussian approximation)]. However, exploratory post-hoc analyses found a significant difference between Meth+Veh and Meth+RTL551 treatment groups [Mann-Whitney test, p = 0.034 (Gaussian approximation)].