Figure 7.

Class 2 kindled seizures induce dendritic targeting of BDNF mRNA in CA3 pyramidal neurons. A, Representative coronal brain sections at the level of the dorsal hippocampus, exhibiting total hybridization of the digoxigenin-labeled riboprobes. Three hours after class 2 kindled seizures, BDNF mRNA is found in the strata lucidum and radiatum of CA3. These representative sections will not fully correlate with the mean changes in the dendritic BDNF mRNA levels shown in B because of slight differences among the three to six animals of each group. B, Densitometric analysis of the effects of kindling. The left panel shows the densitometric analysis of the dendritic labeling, expressed as pixel intensity (0-255 gray levels; 255 = white; 0 = black) as a function of the distance from the cell soma (in micrometers). Data are the mean of sham-stimulated (control; thin line; n = 4) and class 2, 3 hr (class 2, 3h; thick line; n = 5). The other panels report the changes in BDNF mRNA levels in the different layers of CA3. No significant changes were observed in other hippocampal subfields nor at other stages of kindling development. Analysis was performed as described in Materials and Methods. Data are the mean ± SE of three to six animals per group. ^***p < 0.001 versus control values (□); ANOVA and posthoc Newman-Keuls test.lac-mol, Stratum lacunosum-moleculare; luc, stratum lucidum; rad, stratum radiatum. Scale bar: whole hippocampus, 750 μm; CA3, 150 μm.