Trisomic mice continued to drink significantly more CS on second exposure than disomic mice.

<p>There was no significant difference in degree of preference during first exposure between disomic and trisomic animals. During the second exposure disomic mice had a greater avoidance of the CS than the trisomic animals (* p<0.05). Treatment did not preferentially affect CTA learning and affected both karyotypes to the same degree. Mean ± SEM shown.</p

Treatment with mNPC significantly increased the density of the granule cells and decreased their diameter.

<p>A. There was no difference in the density of granule cells between disomic and trisomic mice overall. However, treatment with mNPC significantly increased the density of the granule cells (p<0.05). While this effect is more clearly observable in the disomic/NPC group (#), the interaction between treatment and karyotype suggests that mNPC effect was present in both karyotypes. B. Animals implanted with mNPC had granule cells with significantly smaller cell soma than untreated or saline treated animals (p<0.05). Again, this is best observed in the disomic group (#) although statistically both mNPC groups were affected. Mean ± SEM shown.</p

Novel alternations did not differ but mNPC treatment increased Trisomic performance above chance performance.

<p>Overall, trisomic mice showed significantly fewer novel alternations compared to disomic mice (* p<0.05). Treatment with either saline or mNPC did not significantly change the number of novel alternations in either karyotype compared to their respective controls. However, trisomic mice treated with mNPC alternated significantly above chance alone (solid line), while untreated and saline treated trisomic mice did not. Mean ± SEM shown. * Significant main effect of karyotype. ∧ Novel alternations were significantly above chance.</p

GFP+ cells found in areas outside of the hippocampus.

<p>A. Half of trisomic mice had GFP+ cells in the entorhinal cortex (arrows). B. GFP+ cells were found near the lateral ventricles in the septum (arrows). C. GFP+ mNPC also were found in the CC and again in the underlying septal areas (arrows). rf, rhinal fissure; lv, lateral ventricles; CC, corpus callosum. Scale Bars in A = 100 µm and in B–C = 200 µm.</p

All groups recognized the novel object.

<p>All groups exhibited a preference for the novel object, as indicated by a DI above zero. While there is apparent variability, the differences in the DI between groups did not reach significance (p>0.05). Mean ± SEM shown.</p

Organizational differences in the granule cells of the DG.

<p>Untreated disomic brains (A) had a lower density of granule cells, with a correspondingly larger cell diameter. Similar results were reported for untreated trisomic mice (C). In both groups, the granule cell layer appears less organized in that there was more space between the cells (arrows in A) and randomness to their location within the layer. In contrast, in the Disomic/mNPC mice (B) and Trisomic/mNPC mice (D), both of which had smaller cell diameters and a tendency towards a higher cell density, have a more organized appearance. The granule layers of these groups have tightly aligned cells, which sometimes appear to be in rows and columns (arrow heads in B). Scale bars in A–D are equal to each other and represent 100 µm.</p