Fig. 1: In an AD mouse model (J20), CA1 pyramidal neurons display spatially restricted loss of mitochondrial biomass and dendritic spine loss in distal apical tufts.
a, b Representative images of CA1 PN dendritic segments from different layers of WT control and J20 mice. CA1 PNs were electroporated with pCAG-Venus and pCAG-mito-DsRed by in utero electroporation in E15.5 WT and J20 mouse embryos. Both mouse groups were fixed and imaged at 3-months postnatal (P90). Dendrites from basal, oblique, and distal apical are magnified to show spine density and mitochondrial morphology. The three types of dendritic segments were imaged in three distinct layers as depicted in b for both WT and J20 mice. c–e Quantification of spine density (c), individual mitochondrial length (d), and mitochondrial density (e), measured as the fraction of a dendritic segment length occupied by mitochondria. In panels c–e, data are represented by box plots displaying minimum to maximum values, with the box denoting 25th, 50th (median), and 75th percentiles from at least three independent in utero electroporated mice. nBasal WT = 47 dendrites, 595 mitochondria; nBasal J20 = 32 dendrites, 495 mitochondria; nOblique WT = 46 dendrites, 630 mitochondria; nOblique J20 = 33 dendrites, 507 mitochondria; nDistal WT = 39 dendrites, 284 mitochondria; nDistal J20 = 32 dendrites; 426 mitochondria. All of the analyses were done blind to the experimental conditions and were manually counted using FIJI. Statistical analyses were performed using Mann–Whitney test (c–e). Exact P values are indicated on the figure when available through Prism software, otherwise, the test significance is provided using the following criteria: ***P < 0.001; ****P < 0.0001. Scale bar = 2 μm.
