Free amino acids in post-mortem cerebral cortices from patients with Alzheimer-type dementia.

Concentrations of free amino acids were measured in the cerebral cortices of post-mortem brains from 5 histologically verified cases of Alzheimer-type dementia (ATD) and 8 histologically normal controls. The concentration of glutamate in the ATD brains was significantly lower in the superior frontal, orbital, cingulate and inferior temporal cortices when compared with the control brains. The concentrations of taurine and gamma-aminobutyric acid in the ATD brains were significantly lower in the inferior temporal cortex. These findings suggest that amino acid neurons could be involved in ATD.