Long-term estrogen therapy and 5-HT2A receptor binding in postmenopausal women; a single photon emission tomography (SPET) study

Long-term ET may be associated with lower 5-HT2A receptor availability in hippocampus. This may reflect increased activity within the serotonergic pathway leading to down-regulation of post-synaptic receptor. Also, increased availability of the 5-HT2A receptor in hippocampus is associated with poorer memory function.