Fig. 12

Significant neuronal loss in hippocampus of AD-like aged degu brains. Confocal microscopic images demonstrate the distribution of neurons labeled by NeuN immunoreactivity (red, a specific marker for neurons) in the hippocampus. (a, b) A low-magnification image shows NeuN-labeled neurons in CA1 and dentate gyrus (DG) regions in a Non-AD degu coronal brain section. c, d A higher magnified view of the boxed area in (a) shows NeuN-labeled pyramidal neurons in distal CA1. e, f An overview image shows a notable loss of NeuN signal in the distal CA1 region in an AD-like aged degu brain. g, h A higher magnified view of the boxed area in g highlights NeuN signal missing in the distal CA1 (the area between two dotted lines). Cell nuclei are counterstained by DAPI (blue) in b, d, f, h. Note that overlap in DAPI (blue) and NeuN (red) signal results in magenta color. (i) Quantification of NeuN-positive cells in CA1 shows significantly fewer neurons in AD-like degu brain compared to Non-AD control (p = 0.0006714) and a trend towards greater loss in AD-like female degus compares to AD-like males (p 0.076432). Error bars represent SEM; ***p < 0.001, n = 6 degus in AD-like and Non-AD groups, n = 3 for male AD-like and female AD-like groups