Postmortem analysis of Arc response probability in cortical and hippocampal neurons with and without NFTs. (a, b) Immunohistochemical staining of medial extrastriate visual cortex (a) and CA1 field of the hippocampus (b) of an rTg4510 mouse. NeuN immunolabeling is shown in cyan, direct dVenus fluorescence in green and thiazine red labeling of tangles in red. Scale bar = 25 μm. Arrowheads in a and b point to Arc::dVenus-positive neurons with tangles. (c, d) Stereological estimations of the percentage of neurons with tangles based on counts of NeuN-, dVenus- and thiazine red-positive neurons in the medial extrastriate visual cortex (c) and CA1 (d). Data presented as means ± s.e.m.; n.s., not significant, P = 0.96 in c, P = 0.84 in d. N = 4 mice, 4273 neurons (visual cortex) and 441 neurons (CA1). (e,f) Forest plot of odds ratios (ORs) of NFTs affecting neuronal Arc responses in extrastriate medial visual cortex (e) and CA1 field of the hippocampus (f). Presented data were acquired from the analysis of stereological counting of neurons using Fisher’s exact test and shown as OR ± 95% confidence interval on a log10 scale.