Fig. 4

Brain-injured mice overexpressing IGF1 more rapidly learn to find a novel platform location. (a) Brain-injured wildtype (WT) and IGF1 transgenic (IGFtg) mice learned to find a hidden platform during radial arm water maze (RAWM) acquisition testing (Days 1–2). Both WT and IGFtg mice show a decrease in numbers of errors over training days. Sham control WT mice from a separate study are shown as a reference. (b) Heat maps illustrate activity patterns for representative IGFtg and WT mice during the first three blocks of reversal testing on Day 3 in the RAWM. IGFtg mice extinguished memory of the old goal arm sooner, after the platform was moved from the original training location (old arm; denoted by a green square) to a novel location (novel arm; denoted by red asterisk). Heatmap blue to red coloration indicates increasing amount of time. (c) Both WT and IGFtg mice show a decrease in numbers of errors during RAWM reversal testing. (d) WT mice consistently spent more time than the IGFtg mice in the previous platform location during RAWM reversal testing. (e) Injured WT and IGFtg mice have similar times to locate a visible platform at 6 weeks after CCI, confirming that differences between groups during the hidden platform trials were not due to sensory or motor dysfunction. CCI n = 9–11/genotype; Repeated measures ANOVA. *p < 0.05, main effect of genotype (in D) or block (in E)