Fig. 2: Necrosis occurs most actively at the preclinical stage in mouse and human AD brains.

a Morphological definition of active necrosis, secondary necrosis and ghost of cell death. Active necrosis is specified by a single degraded nucleus detected by DAPI surrounded by pSer46-MARCKS-positive degenerative neurites. Secondary necrosis is a cluster of multiple dying cells with residual Aβ in extracellular space and surrounding pSer46-MARCKS stains. Ghost of cell death is an extension of secondary necrosis in which DAPI and pSer46-MARCKS stains have faded out. b Upper graphs show time course of active necrosis, secondary necrosis and ghost of cell death in 5xFAD mice, in retrosplenial dysgranular cortex. Representative images from each time point are shown below the graph. Yellow arrow indicates a single degraded nucleus surrounded by reactive pSer46-MARCKS stains. N = 3 mice, n = 30 fields. c Time course of active necrosis in human mutant APP knock-in mice. Time course of necrosis (N = 3 mice, n = 30 fields) and representative images are shown. d Representative images of active necrosis in human MCI (MCI) and non-neurological disease control (NC). Rupturing or deformed nucleus undergoing necrosis is surrounded by Aβ and pSer46-MARCKS-positive degenerative neurites (white arrow). e The box plot shows the number of active necrosis per visual field in the median, quartiles and whiskers that represent 1.5× the interquartile range. **p < 0.01, Tukey’s HSD test (n = 10 images/person). f Simulation of active necrosis. A formula was generated by assuming that cell death occurs at a constant rate in the residual neurons and in regular time interval (top). Modulation of each parameter changed simulation curves (graphs). g Numerical simulation program generated the optimized curve (red line) based on observed values of active necrosis in occipital cortex of 5xFAD mice (black line) and predicted parameter values and active necrosis at an unmeasured time point (2 months). h The number of active necrosis observed afterwards with samples at 2 months (60 days) matched exactly with the predicted number. Values in each group are summarized by mean ± S.E.M. Source data are provided as a “Source Data file”.