Research Paper Volume 13, Issue 2 pp 2681—2699

Neuritin-overexpressing transgenic mice demonstrate enhanced neuroregeneration capacity and improved spatial learning and memory recovery after ischemia-reperfusion injury

Neuritin overexpression improves recovery of spatial learning and memory following transient global ischemia. (A) Morris water maze (MWM) schedule and experimental design. Dark boxes represent days after TGI, of which, black boxes represent critical stage of nerve repair. White boxes represent days of Morris water maze. MWM experiments started from on day 2 and ended on day 7 of TGI. (B) Escape latencies on the visible platform trials (day 1) and hidden platform trials (days 2–5). There were no group differences in escape latencies among groups in visible platform trials. Latencies decreased progressively during hidden platform trials, but faster in the Tg-TGI group than the WT-TGI group. (C) Bar graph showing no significant group differences in escape latencies on visible platform trials (day 1) but significantly shorter latencies for Tg-TGI and sham groups on the final two invisible platform trial days (days 4 and 5). (D−F) Results of the probe trial for spatial memory (day 6). (D) Tg-TGI mice made significantly more crossings of the original platform position than WT-TGI mice. (E) Tg-TGI mice spent significantly more time in the original platform quadrant than WT-TGI mice. (F) Example swim paths demonstrating distinct search strategies by Tg-TGI and WT-TGI mice (targeted vs. random). Data are presented as mean ± SEM (Sham: n=12, WT-TGI: n=12, Tg-TGI: n=11). Legend: *pp

Figure 5. Neuritin overexpression improves recovery of spatial learning and memory following transient global ischemia. (A) Morris water maze (MWM) schedule and experimental design. Dark boxes represent days after TGI, of which, black boxes represent critical stage of nerve repair. White boxes represent days of Morris water maze. MWM experiments started from on day 2 and ended on day 7 of TGI. (B) Escape latencies on the visible platform trials (day 1) and hidden platform trials (days 2–5). There were no group differences in escape latencies among groups in visible platform trials. Latencies decreased progressively during hidden platform trials, but faster in the Tg-TGI group than the WT-TGI group. (C) Bar graph showing no significant group differences in escape latencies on visible platform trials (day 1) but significantly shorter latencies for Tg-TGI and sham groups on the final two invisible platform trial days (days 4 and 5). (DF) Results of the probe trial for spatial memory (day 6). (D) Tg-TGI mice made significantly more crossings of the original platform position than WT-TGI mice. (E) Tg-TGI mice spent significantly more time in the original platform quadrant than WT-TGI mice. (F) Example swim paths demonstrating distinct search strategies by Tg-TGI and WT-TGI mice (targeted vs. random). Data are presented as mean ± SEM (Sham: n=12, WT-TGI: n=12, Tg-TGI: n=11). Legend: *p<0.05; **p<0.01 versus WT-TGI and sham, respectively, by one-way analysis of variance (ANOVA) followed by LSD tests for pair-wise comparisons.