Contextual Fear Memory Formation and Destabilization Induce Hippocampal RyR2 Calcium Channel Upregulation

Figure 4

Memory extinction promotes RyR2 upregulation in situ. (a) Representative confocal images of RyR2 immunofluorescence (green) and Hoechst nucleus stain (blue) obtained from CA1, CA3, and DG region of the hippocampus. Samples were obtained 29 h after training (T29) or 5 h after the 15 min reexposure session (R15). Samples from naïve rats were used as control. Scale bar: 20 μm. (b) Bar graphs showing the quantification of RyR2 immunofluorescence pixels normalized by nuclear stain present in regions enriched in nuclei in CA1, CA3, and DG. (c) Bar graphs showing the quantification of RyR2 immunofluorescence pixels, normalized by the nuclear stain present in the entire images of CA1, CA3, and DG. Values represent mean ± SE; for samples from the control and T29 groups; for the R15 group. Statistical analysis was done with one-way ANOVA (CA1 , CA3 , and DG ) followed by Tukey’s multiple comparison post hoc test; ; with respect to naïve and T29, respectively.

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