Fig. 4:

Immunohistochemical staining of healthy human brain reveals heterogeneity in perineuronal net labeling that differs between brain regions A Representative micrographs of the distribution of either ACAN or WFL labeling across the human vmPFC (N = 11), EC (N = 8) and HPC (N = 8). Imaged at 20X on Evident Scientific VS120 Slide Scanner, scale bar 500μm. B PNNs were manually classified as either single (WFL+/ACAN− or WFL−/ACAN+) or double (WFL+/ACAN+, pink arrows) labeled. ACAN staining can be found either intracellularly (100% colocalization with NeuN, cyan arrow) or in the distinctive pattern of an extracellular PNN (surrounding NeuN, yellow arrow), only the latter was considered as an ACAN+ PNN in this study (yellow arrow). Imaged at 40X on Evident Scientific FV1200 Confocal, scale bar 25μm. C Comparison of the labeling patterning between the different brain regions investigated (ANCOVA with age as covariate: labeling × region: F(3,46) = 25.3, p < 0.001). D Total ACAN (WFL+/ACAN+ and WFL−/ACAN+) and total WFL (WFL+/ACAN− and WFL+/ACAN+) labeling can be found in different amounts depending on the brain region (ANCOVA with age as covariate: total labeling × region: F(2,23) = 19.5, p < 0.001). Within the vmPFC the two markers label similarly, while WFL prevails in the EC and ACAN predominates in the HPC. WFL: Wisteria Floribunda Lectin, ACAN: anti-aggrecan core protein, NeuN: anti-neuronal nuclei, vmPFC: ventromedial prefrontal cortex, EC: entorhinal cortex, HPC: hippocampus, ANCOVA: analysis of co-variance.