S. Kumashiro et al., FREE D-SERINE IN POSTMORTEM BRAINS AND SPINAL-CORDS OF INDIVIDUALS WITH AND WITHOUT NEUROPSYCHIATRIC DISEASES, Brain research, 681(1-2), 1995, pp. 117-125
We have measured the concentrations of free D-serine post-mortem in th
e prefrontal cortex, parietal cortex, cerebellum and spinal cord from
individuals with and without (controls) neuropsychiatric diseases usin
g high-performance liquid chromatography with fluorometric detection.
The levels of D-serine were found to be high in the prefrontal and par
ietal cortex (around 100 nmol/g wet weight) and very low in the cerebe
llum and spinal cord (below 10 nmol/g wet weight). The uneven distribu
tion of the D-amino acid in the human central nervous system (CNS) res
embles that observed in rodents, suggesting that, as shown in the rat
CNS, the regional variation of D-serine content in the human brain mig
ht also be closely correlated with those of the N-methyl-D-aspartate (
NMDA) type excitatory amino acid receptor. In the prefrontal cortex, t
he gray and white matter had a similar concentration of D-serine. Thes
e findings, together with the selective action of D-serine at the NMDA
-related glycine site and the non-neurogenic nature of extracellular D
-serine release, add further support to the view that D-serine could b
e an intrinsic modulator of the NMDA receptor liberated from certain g
lial cells in the mammalian brain. Despite the anti-psychotogen activi
ty of D-serine in the rat, there were no statistically significant dif
ferences between the D-serine contents in the prefrontal or parietal c
ortex of controls and those of patients with schizophrenia or dementia
of the Alzheimer type.