Hippocampal estrogen beta-receptor immunoreactivity is increased in Alzheimer's disease

Post-menopausal estrogen use reduces the risk and severity of Alzheimer's disease (AD). The present study investigates the distribution of both estrogen receptors ER alpha and ER beta in the human hippocampus in aged controls and in AD cases with immunohistochemistry. No ER alpha immunoreactivity was observed both in controls and in AD cases. On the other hand, ER beta was observed in some neuronal cells in the hippocampal subfields CA1--4, in astrocytes and in extracellular deposits both in controls and AD cases. The ER beta immunoreactivity was distinctly increased in all AD cases in cellular and extracellular localizations indicating a role for ER beta-mediated estrogen effects in AD-related neuropathology. This study provides the first demonstration of ER beta in human hippocampus in aged controls compared to AD cases.