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

Figure 7

Hilar c-fos labeling is greatest in animals exposed to novelty and relatively unaffected in the GCL. (a) Hilar c-fos labeled cells are shown for the following 3 groups (mean, SD): mice exposed to familiar objects (FO), mice exposed to novel objects (NO), and mice with no prior exposure to objects (no habituation; NH). (a, 1) Hilar c-fos-labeled cell counts were normalized to the mean of the cohort. A one-way ANOVA showed a significant effect of exposure (; ) with the c-fos+ cells of the familiar group significantly less than the novel object group () and no habituation group (). The novel object group showed significantly fewer c-fos cells than the group with no habituation (). (a, 2) Normalized GCL c-fos+ cell counts did not exhibit statistical differences (one-way ANOVA, ; ). (b) Comparison of FO, NO, and NH for 3 cohorts. (b, 1) Hilar c-fos cell numbers are shown for all animals. The data are organized into 3 cohorts, with 2 animals/behavior for each cohort. Data for individual animals are designated by circles; means are indicated by bars between the circles. Red: FO; blue: NO; green: NH. Note the same pattern for each cohort, i.e., FO<NO<NH. (b, 2) c-Fos cell numbers are shown for the GCL. Data for each cohort do not indicate a consistent difference between FO, NO, and NH.