Regional distribution of amino acid transmitters in postmortem brains of presenile and senile dementia of Alzheimer type.

We measured the concentrations of glutamate, aspartate, and gamma-aminobutyrate (GABA) in cortical and subcortical areas by an enzymatic fluorometric method in 9 patients with histologically verified Alzheimer's disease and senile dementia of the Alzheimer type (AD/SDAT), and in 10 age-matched normal control subjects. When compared with controls, the concentration of glutamate in cortical and subcortical areas of AD/SDAT brains was significantly reduced. The concentrations of aspartate and GABA were also reduced in several areas, but the magnitude of reduction was less than that of glutamate. This apparent reduction of glutamate in postmortem brains might have a bearing on pathophysiological mechanisms in AD/SDAT.