Figure 1.

d-Serine distribution in the rat cerebral cortex. A, Confocal microscopy analysis of immunostainings of d-serine versus astroglial [glutamine synthase (GS)] or neuronal (β3-tubulin) markers in the rat cerebral cortex. Arrowheads, d-Serine-containing neurons; arrows, d-serine-positive astrocytes; Control, staining with a nuclear marker, DAPI (blue), and an anti-d-serine antibody previously preabsorbed with 500 μm liquid-phase d-serine glutaraldehyde conjugate. Scale bars, 30 μm. B, Representative electron micrographs of d-serine preembedding immunohistochemistry using the peroxidase method showing that d-serine immunoreactivity is mainly distributed in astrocytic processes (arrows) at the level of asymmetric synapses in the rat cerebral cortex. C, Representative low-magnification (top) and high-magnification (bottom) electron micrographs showing that no peroxidase staining is detected with a preabsorbed anti-d-serine antibody. Ast, Astrocyte; D, dendrite; S, dendritic spine; B, axonal bouton. Scale bars, 500 nm.