Figure 3

Time to mount the hidden platform (top panel) and swimming distance to the platform (bottom panel) during the first trial of the second (young-adult) water maze test. Rats were treated (through the maternal circulation) with either 100 mg/kg ketamine HCl (i.p.) or saline on either E18 or E19 and then tested later on P81. The temporal data presented here do not include time spent treading water but rather represent only the time that the rats were making forward progress. Ketamine-treated rats found the platform significantly faster than saline controls and swam shorter distances to do so. Group comparisons indicated that rats treated with ketamine on E18 or E19 reached the hidden platform significantly faster and swam shorter distances than saline-treated controls (* = p ≤ 0.05; NS = non-significant group differences). Further, E18 rats treated with ketamine later exhibited a shorter latency to reach the hidden platform than did E19 rats treated with ketamine. Data were analyzed using a two-way ANOVA [Drug (100 mg/kg ketamine HCl, saline control) X Treatment age (E18, E19)]. Individual group comparisons were accomplished by using t-tests employing the Bonferroni compensation for multiple comparisons. Variance indicators are the Standard Error of the Mean (SEM).