E6-AP protein levels were restored to wildtype levels in the TR2-UBE3A treated AS mice.

<p>(A) Representative coronal slices through the hippocampus from each group stained for E6-AP. (B) Quantitative analysis of the IHC revealed a significant increase in E6-AP expression in the WT and AS-TR2-UBE3A mice compared to the AS TR2-GFP group, while there was no significant change between the WT and AS TR2-UBE3A mice. Results shown represent the mean with standard error.</p

AS TR2-UBE3A mice had significant improvements in the Morris water maze.

<p>(A) Escape latency to reach the platform during 5 days of training in Morris water maze. The only significant differences seen were an increase in latency for the AS TR2-GFP mice on day 3 and a decrease in latency for wildtype mice on day 4 compared to the other two groups (2-way ANOVA Bonferroni: Interaction [F(8,100) = 1.01, <i>P>0.05</i>]; Treatment [F(2,100) = 5.30, <i>P<0.05</i>]; Time [F(4,100) = 53.49, <i>P<0.0001</i>]; Matching [F(25,100) = 5.37, <i>P<0.0001</i>]). The target platform is indicated by the black circles. (B) Quantification of the number of platform crossings in the target (T), opposite (O), right (R), and left (L) quadrants during the probe trial of the Morris water maze 24 hours after training indicate no significant differences among any of the groups in comparing target platform crossings to opposite platform crossings (ANOVA Tukey WT: [F(3,35) = 9.546, <i>P<0.0005</i>]; AS TR2-GFP: [F(3,35) = 3.186, <i>P<0.01</i>]; AS TR2-UBE3A: [F(3,39) = 2.814, <i>P<0.05</i>]). All three groups learned the platform location based on a spatial bias as indicated by the time spent in the target quadrants (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0027221#pone-0027221-g005" target="_blank">Fig. 5D</a> 24 h ANOVA Tukey [F(2,26) = 1.027, <i>P>0.05</i>]) (C) A probe test 72 hours after training indicate that the WT and AS TR2-UBE3A groups had significantly more target platform crossings compared to the number of opposite platform crossings (ANOVA Tukey WT: [F(3,35) = 6.086, <i>P<0.005</i>]; AS TR2-GFP: [F(3,35) = 0.5650, <i>P>0.05</i>]; AS TR2-UBE3A: [F(3,39) = 2.679, <i>P<0.05</i>]), but this improvement was not spatially biased as seen by the time spent in the target quadrant (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0027221#pone-0027221-g005" target="_blank">Fig. 5D</a> 72 h ANOVA Tukey [F(2,25) = 5.067, <i>P<0.02</i>]). Results shown represent the mean with standard error.</p

Increasing E6-AP in the AS mouse results in improvements in early phase LTP.

<p>(A) AS TR2-GFP mice have significant deficits in hippocampal synaptic plasticity. LTP was induced following 20 min of baseline recordings. (B) Immediately following TBS, acute hippocampal slices taken from AS TR2-GFP mice had significant deficits in the average PTP (average of first 5 min recordings of fEPSPs slopes). To compare late phase LTP, the last 5 min recordings of fEPSPs slopes were averaged, and there was no significant difference between any of the groups. (C) There were no significant differences between any of the groups in either PPF or (D) PTP, indicating that short term synaptic plasticity mechanisms are unaffected. Results shown represent the mean with standard error.</p

There were no changes in motor coordination, activity levels, or anxiety.

<p>(A) There was no change in latency to fall of the rotorod in either AS group. (B) Total distance travelled during the open field test revealed no significant difference between any of the treatment groups. (C) Time spent in the open arms of the elevated plus maze was used to determine general anxiety. (D) Time spent immobile in the elevated plus maze was not significantly different in any of the groups. Results shown represent the mean with standard error.</p

AS mice receiving TR2-UBE3A had significant improvements in associative learning.

<p>(A) There were no differences during the training phase of fear conditioning, indicating that all groups of mice were capable of freezing to the same extent. (B) AS TR2-GFP mice show significant deficits in contextual fear conditioning when assessed 24 h after training. AS TR2-UBE3A mice, however, froze at the same rate as the wildtype mice. Results shown represent the mean with standard error.</p