Novelty and Novel Objects Increase c-Fos Immunoreactivity in Mossy Cells in the Mouse Dentate Gyrus

Figure 8

Septotemporal distribution of hilar and GCL c-fos expression in response to familiar objects (FO), novel objects (NO), and no habituation (NH). (a, 1) The numbers of c-fos+ hilar cells are shown for the same animals as Figure 5, plotted from the most ventral [34] to dorsal [56] levels. A two-way RMANOVA showed a significant effect of the task (FO: red; NO: blue; NH: green; ; ) and ventral-dorsal location (; ), and there was no interaction of factors (; ). Tukey’s post hoc tests showed significance () at discrete locations along the septotemporal axis as indicated by symbols. ; ; ; . (a, 2) Data are shown for GCL c-fos+ cells. A two-way RMANOVA showed no statistical effect of the task (; ), but it showed a significant effect of the ventral-dorsal location (; ) with the most dorsal level exhibiting differences by Tukey’s post hoc tests (). There was a significant interaction (; ) because only the most dorsal level showed significant differences between the tasks by Tukey’s post hoc tests. (b, 1) An analysis of the data from (a) is shown, pooling all ventral sections [5, 34, 35, 89] and comparing them to all dorsal sections [1, 57, 65, 73]. Totals are also shown (all 8 sections). A two-way ANOVA showed significant ventral-dorsal differences (; ) and a significant effect of the task (FO, NO, or NH: ; ). There was no interaction of factors (; ). Tukey’s post hoc tests showed the significant differences of each task when comparisons were made of ventral vs. dorsal levels (e.g., ventral FO vs. dorsal FO, ventral NO vs. dorsal NO). For the ventral data, there were additional significant differences between FO and NO as well as FO and NH. For the dorsal data, FO vs. NH was significant by Tukey’s post hoc test. A one-way ANOVA for pooled data (total) showed significant differences between tasks (; ) and Tukey’s post hoc tests were significant for all comparisons (FO vs. NO, FO vs. NH, and NO vs. NH). (b, 2) The ventral and dorsal data for the GCL are shown. A two-way ANOVA showed ventral-dorsal differences (; ) but no differences between tasks (; ) and no interaction (; ). Within ventral levels, there were no differences between tasks. For dorsal levels, FO vs. NO was significant. When all levels were pooled (total), a one-way ANOVA showed no significant differences between tasks (; ).

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