Figure 1. The pathology of Alzheimer’s disease .
amyloid plaques, neurofibrillary tangles and degeneration of multiple neurotransmitter systems. a. A tissue section from region CA1 of the hippocampus of an Alzheimer’s patient exhibits many neurofibrillary tangle-bearing pyramidal neurons and neuritic plaques, examples of which are demarcated. In addition, diffuse amyloid deposits (yellow) are present. b. Hippocampal pyramidal neurons receive synaptic inputs from several different types of neurotransmitters including excitatory glutamatergic and inhibitory GABAergic inputs from intrinsic hippocampal neurons, and modulatory inputs from cholinergic neurons in the basal forebrain, serotonergic neurons in the raphe nucleus and noradrenergic neurons in the locus ceruleus..