D-SERINE : AN EXCEPTIONAL D-AMINO ACID IN BRAIN

"In contrast to L-isomer domination of amino acids among mammalian tissues, D-serine functions as a neurotransmitter in brain", a study reveals. It acts on high affinity site on NMDA (M-methylD-aspartate) receptor. It's involved in an important role in glial cell neurotransmission or gliotransmission. Serine racemase, the enzyme which produces D-serine is also found widely distributed in brain tissues.

Both NMDA receptors and astrocytes are key players of glutamate linked metabolism in neural tissues. However, exact role of D-serine in brain glutamate metabolism is yet to be determined.



d‐Serine localizes to neurons and astrocytes in the brain. Staining for d‐serine was performed in pyramidal neurons of layer V of the cerebral cortex and in astrocytes in the corpus callosum of a P9 rat. The lower panels depict double‐labeling immunofluorescence for d‐serine (labeled for SR in the original publication) and a neuronal nucleus marker (NeuN) in layer VI of the cerebral cortex of a P9 rat. Reproduced with slight modifications from Kartvelishvily et al.

Source: 

d‐Amino acids in the brain: d‐serine in neurotransmission and neurodegeneration.             Herman Wolosker, Elena Dumin, Livia Balan,Veronika N. Foltyn.
FEBS Journal. Dec 31, 2010. Pages 3514-3526