Fig. 1. WFA-labeled perineuronal nets and glial cells in the human amygdala and co-labeling of WFA and GFAP. WFA lectin histochemistry resulted in labeling of perineuronal nets (A, B) and glial cells (C, D) in the human amygdala. A and B represent confocal and light microscopy (DAB with methylgreen counterstaining) photomicrographs, respectively, of WFA-labeled perineuronal nets. Note the large size with respect to glial cells (C), the characteristic neuronal morphology and the hollow appearance. These characteristics contrast sharply with those of glial cells showing intracellular WFA labeling, shown in C and D as light microscopy and confocal photomicrographs, respectively. These cells have small cell bodies and ‘bushy’, tightly packed, short processes. The large majority of WFA-labeled, putatively CSPG-expressing, glial cells were also GFAP-immunoreactive. In D, E, and F, confocal photomicrographs of a glial cell labeled with WFA (D, green), GFAP (E, red) and the overlay of the markers (F, yellow). Scale bars are 50 µm A, D, E, and F; 37 µm B, C.

Fig. 2. Glial cells expressing chondroitin sulfate proteoglycans may represent a subpopulation of astrocytes in the human amygdala. Schematic representation of the distribution of GFAP-immunoreactive cells (A), WFA-labeled glial cells (B), and WFA-labeled perineuronal nets (C) in the LN, BN, ABN and CO from one representative section of the amygdala in subject 14.

Fig. 3. WFA-labeled glial cells show a consistent pattern of segregation within subregions of the human amygdala. Schematic representation of the distribution of WFA-labeled glial cells in four sections from the BLC-CO in subjects 5, 23, 14, 28, and 43. The majority of these cells clustered between the medial LN and the parvicellular BN as well as along the ventral edge of these nuclei. Small cell clusters were also detected in the magnocellular BN and in the dorsal portion of the ABN and CO.

Fig. 4. Intracellular WFA labeling in glial cells was not detected in the rodent and nonhuman primate amygdala. Light microscopy photomicrographs showing WFA-labeled perineuronal nets (arrowheads) and glial cells (arrows) in the ventrolateral subdivision of the LN in human (A), WFA-labeled perineuronal nets (arrowheads) in the ventrolateral subdivision of the LN of a rhesus monkey (B) and in the BN of an adult (P60) rat (C). WFA-labeled glial cells were not detected in the amygdala of rhesus monkeys and rats. Scale bars, A, B 50 µm; C 100 µm.

Total numbers and numerical densities of WFA-labeled, putatively CSPG-expressing, glial cells in human BLC-CO

Numerical density is expressed as cells/mm³.

Demographic and descriptive data of the human subject cohort

cases used for CSP-GFAP double labeling.

^mean ± standard deviation.

Abbreviation: PMI, postmortem time interval.