Figure 8

Pde4d KD and context learning modify multidimensional spine density in HC and RSC. Multidimensional spine density histograms of HC stratum radiatum (A) and RSC layer 2/3 apical (B) dendrites were derived by plotting spine densities as a function of spine length x head diameter for each sample (50 µm dendritic length) across a 2D grid at intervals of 0.125 µm for each measure followed by interpolation. Group values (spine density) represent the grid mean values (per 10 µm dendrite) for all cells tested per group (top of panel A/B). Difference plots (Δ spine density, bottom of panel A/B) were derived by comparing group mean values for each group versus shGFP (naïve). Note changes in RSC observed in trained shGFP controls, which are not captured with the classical categorization of spines into thin, mushroom, and stubby spines shown in Fig. 7.