a, Nissl stains of prefrontal neocortex with higher magnification of boxed area below, demonstrating preserved neuronal structure and anatomical cytoarchitecture in BEx brains. Scale bars, 350 μm (top), 100 μm (bottom). Images are from a representative brain from each condition; experiments were repeated in n = 6 independent brains per group with similar results. b, Nissl stains of primary motor cortex reveal preserved Betz cell structure (arrows) under BEx perfusion conditions, despite these cells having been axotomized following decapitation. Despite similar brain region analysis, question marks denote uncertainty of Betz cell identity due to stark cellular disintegration. Images are from a representative brain from each condition; experiments were repeated in n = 3 independent brains per group with similar results. c, Confocal tile scans of immunohistochemical stains for NeuN (green) in the prefrontal neocortex. Scale bar, 50 μm. Images are from a representative brain from each condition; experiments were repeated in n = 6 independent brains per group with similar results. d, Maximum intensity confocal projections of NeuN staining. Neurons exhibit a swollen morphology in 1 h PMI brains, and significant cellular destruction under 10 h PMI and CP conditions (arrowheads), while neurons in the BEx condition display typical elongated morphology (arrows). Scale bar, 50 μm. Images are from a representative brain from each condition; experiments were repeated in n = 6 independent brains per group with similar results. e, Maximum intensity projections of NRGN staining (green) show preservation of typical morphology of cortical pyramidal neurons under BEx perfusion (arrows), with swollen morphology under 1 h PMI conditions (red arrow). There is evidence of clear cell destruction and the presence of enlarged vacuoles under the 10 h PMI and CP conditions (arrowheads). Scale bar, 50 μm. Images are from a representative brain from each condition; experiments were repeated in n = 6 independent brains per group with similar results. f, Maximum intensity projections of GAD1 staining (red). In 10 h PMI and CP specimens, GAD1 staining reveals contracted cell bodies (arrows) with a loss of GAD1-positive somal contacts as compared to 1 h PMI and BEx brains. Scale bar, 50 μm. Images are from a representative brain from each condition; experiments were repeated in n = 6 independent brains per group with similar results. g, Number of neuronal cells present in the prefrontal neocortex. Data computed from Nissl stains. One-way ANOVA (P < 0.001, F[3,20] = 224.6) with post-hoc Dunnett’s adjustment; n = 6 brains per condition; NS, not significant. h, Percentage of cells that exhibit a swollen, ellipsoid morphology. Data analysed from Nissl stains. One-way ANOVA (P < 0.001, F[3,20] = 16.33) with post-hoc Dunnett’s adjustment; n = 6 brains per group. Mean ± s.e.m. i, j, Total numbers of NRGN+ and GAD1+ cells, respectively, in the neocortex. One-way ANOVA (NRGN+: P = 0.002, F[3,20] = 7.018; GAD1+: P < 0.001, F[3,20] = 9.153) with post-hoc Dunnett’s adjustment. n = 6 brains per group. Mean ± s.e.m.