Figure 4.

Animal behavior tests for evaluating functional consequences of an HI insult in mice. (A) Representative total tracks in the open field test and quantification of duration of movement in the central area representing anxiety as well as frequency of rearing representing exploration tendency. There were no significant changes in the former but there was a decrease in the latter. (B) Swim path traces from the probe test of the Morris maze. A learning ability deficit in the HI group is shown by prolonged escape latency on day 4. No difference in swimming speed indicates general normal motor function. (C) In the probe trial, reduction in space memory ability was shown in a lower percentage of time spent in the target quadrant and fewer platform crossovers. n=8–17 mice/group. sham: without HI. *, P<0.05; **, P<0.01. HI, hypoxia-ischemia.