Figure 6.

SNAP-25b-deficient (MT) mice exhibit slower initial learning acquisition, but more rapid learning of new shock zone, in an active avoidance spatial learning task that is hippocampus-dependent, and increased anxiety-like behaviour, at 4 weeks of age. (a) Daily averages of shock zone entry for MT mice during an active avoidance assay. Initially (day 1), MT mice (n = 9) were slower to learn compared to WT mice (*p < 0.05, Student’s t-test, n = 17). By day 2–3, MT mice were comparable to WT littermates. On days 4–5 (conflict learning) when the shock zone was removed, MT mice entered the shock zone fewer times than that of controls. Each point is mean ± s.e.m. of n animals. (*p < 0.05; Student’s t-test). (b) Relative time spent in the open arms of an elevated plus maze versus total time in the maze. Time spent in the open arm was used as an indicator of anxiety. MT mice (n = 9) spent less time in the open arms consistent with more anxiety-like behaviour, compared to WT controls (n = 17). Total distance travelled in the field was equal, showing that MT mice did not exhibit motor function impairments. Each point is mean ± s.e.m. of n animals.