Amino acid release from biopsy samples of temporal neocortex from patients with Alzheimer's disease

Tissue prisms prepared from neurosurgical samples of temporal neocortex of Alzheimer and control patients, upon depolarization preferentially released aspartate, glutamate and gamma-aminobutyrate (GABA). The Alzheimer and control samples did not significantly differ in the pattern of amino acid release, although acetylcholine synthesis by the Alzheimer tissue prisms was greatly reduced. There was no correlation between the efflux of any amino and acetylcholine synthesis. These observations suggest that in Alzheimer's disease there are no major changes in the extracellular concentrations of these putative amino acid transmitters.