Is senile dementia of the Alzheimer type associated with hippocampal plasticity?

The density of binding sites for excitatory amino acids in the hippocampus of SDAT (senile dementia of the Alzheimer type) patients has been investigated. This was compared to that found in younger and old non-dement cases. In the SDAT hippocampi there was a significant decrease in the glutamate and kainate binding. This reduction correlated positively with the degree of the severity of neurological and pathological disease. In spite of an extensive denervation of SDAT hippocampi, there was no sign of sprouting of mossy fibers; this observation indicates a loss of plasticity in the hippocampus of SDAT patients.