Synaptic slaughter in Alzheimer's disease.

Synaptic loss is currently established as the best neurobiological correlate of the cognitive deficits of Alzheimer's disease (AD) [Ann. Neurol. 27 (1990) 457; Ann. Neurol. 30 (1991) 572]. We provide evidence that still living neurons lose synapses in AD, in addition to the synapse loss due to death of neurons. We also provide evidence indicating that in addition to loss of synapses, synaptic function is also affected in AD by decrements in transcript species related to synaptic vesicle trafficking.