Abstract
Abstract: :
Purpose: D–serine is a potent co–agonist at the NMDA receptor. We have created a new antibody that can detect D–serine in paraformaldehyde–fixed tissues, in order to determine its distribution relative to other neurochemical markers including amino acid neurotransmitters and their transporters. Methods: Antibodies were raised against D–serine using our standard published methods for the production of specific antibodies to small molecules (Pow et al., 1995 J. Neurosci Meths 56:115) and used in double–immunolabelling studies with other markers such as the glutamate transporter GLAST and the glycine transporter Glyt–1. Results: We demonstrate that in the human and rat retina, both radial glial cells and astrocytes contain D–serine. We demonstrate colocalisation with markers such as GLAST and GFAP (which label glial cells) but not with markers such as Glyt–1 (which labels glycinergic amacrine cells). Preliminary studies indicate that in response to insults such as hypoxia there are rapid changes in the levels and distributions of D–serine. Conclusions: Our data suggest that D–serine system may be dynamically modulated under physiological conditions. As the availability of D–serine may influence efficacy of NMDA–mediated neurotransmission we speculate that it may be a significant factor in excitotoxicity in conditions such as glaucoma.
Keywords: Muller cells • excitatory neurotransmitters • neurotransmitters/neurotransmitter systems