[Catecholaminergic systems in the amygdaloid complex of SDAT and aged controls: tyrosine hydroxylase...

Catecholaminergic systems in the amygdaloid complex in patients with senile dementia of Alzheimer type (SDAT) and aged controls have been studied with tyrosine hydroxylase (TH) immunohistochemistry. TH-immunoreactivity was found in fibers in all subnuclei of human amygdala, although varying in density in the subnuclei. The most dense catecholaminergic innervation was observed in the central, basal, and cortical nuclei of amygdala. The prominent finding in the amygdaloid complex of SDAT was that swollen and bulbous TH-immunoreactive neurites were found in association with neuritic plaques, which have not, rarely if any, been found in controls. The numerical density of neurites was mostly in parallel with that of TH-immunoreactive fibers except for the central nucleus. Thus, it is suggested that a class of populations of TH-immunoreactive neurons are selectively affected in the amygdaloid complex in SDAT.