Figure 1.
Behavioral phenotypes in NRG1tg-type I mice: age-emergent locomotor hyperactivity and deficit in spatial short-term memory but not reference memory. (A) Spontaneous locomotor activity (total beam breaks in a 2-h session). NRG1tg-type I mice (triangles; male n = 9, female n = 8) were hyperactive at 12.5 months compared with wt mice (filled squares; male n = 10, female n = 13; P = 0.005). See also Supplementary Materials and Supplementary Figure 2. (B) Spatial working memory: rewarded alternation in the T-maze showing percent correct alternations from 50 trials. At 3–4 months (3 m), NRG1tg-type I mice (gray) did not differ from wt littermates (black), but at 10 months (10 m), NRG1tg-type I mice made fewer correct alternations than wt (P = 0.016). At both time points, wt male n = 10, female n = 14; NRG1tg-type I male n = 9, female n = 9. (C) Single-trial, spatial novelty preference Y-maze task in 10- to 11-month-old NRG1tg-type I (gray; n = 10) and wt (black; n = 16) mice. (C1) Time spent in novel arm minus time spent in the other arm. NRG1tg-type I mice spent relatively less time in the novel arm than wt (F1,22 = 4.21, P = 0.05). (C2) Number of entries into novel arm minus number of entries into other arms. NRG1tg-type I mice made relatively fewer entries into the novel arm than wt (F1,22 = 4.85, P < 0.05). For raw data, see Supplementary Table 2. (D) Spatial reference memory acquisition in an appetitive Y-maze task showing normal performance in 11-month-old NRG1tg-type I mice (triangles, n = 10) compared with wt littermates (filled squares, n = 12); main effect of genotype, F1,20 < 1; genotype by block, F7,140 < 1. Data shown as mean ± standard error of the mean.