I just read this. What does it mean for women on HRT or birth control pills who are already on Lotronox?Love,ECTEstrogen modifies cortical serotonin receptorsSource:ï¿½American Journal of Psychiatry 2003; 160: 1522-4Investigating the effect of estrogen therapy on serotonin receptors in the brain in postmenopausal women. Research suggests that estrogen has a significant effect on serotonin receptors in the brain, which may partly explain the observed beneficial effects of the hormone on cognition and mood. "Prefrontal serotonin 2A (5-HT2A) receptors, shown to increase in rodents following estrogen administration, are one component relating to cognition/mood and actions of antipsychotics/antidepressants," explain Dr. Akira Kugaya (VA Connecticut Healthcare System, West Haven, USA) and colleagues. They carried out positron emission tomography (PET) of 5-HT2A receptor binding with [18F]deuteroaltanserin in 10 postmenopausal women before and after an average of 10 weeks' treatment with estrogen replacement therapy (ERT).The results showed that 5-HT2A receptor binding in the right prefrontal cortex was significantly increased after ERT. Of particular interest, these changes occurred in areas linked to working memory. Supporting these findings, the participants also showed improvements in verbal fluency and trail-making tests after taking ERT. In summary, "estrogen increases 5-HT2A receptor binding in human prefrontal regions," the researchers conclude.