Sensitive silver methods were employed for the examination of extracellular amyloid and intraneuronal neurofibrillary changes in the striatum of Alzheimer's disease patients. Numerous amyloid deposits were present in the striatum whereas neuritic (senile) plaques were only rarely encountered. Many large and a few medium-sized nerve cells had neurofibrillary tangles within their somata and according to morphological criteria corresponded to local circuit neurons. Numerous argyrophilic threads in the neuropil were scattered throughout the nuclear gray matter. The striatum of non-demented individuals was virtually devoid of amyloid and neurofibrillary changes.