Neuroprotective effects of estradiol in mesencephalic dopaminergic neurons

There is a gender difference, or male predominance, in Parkinson's disease and attention deficit hyperactivity disorder (ADHD). Although the reason wh y it is predominantly the male who suffers from the diseases is still unkno wn, the female steroid hormone may be involved in the pathogenesis. Estroge n is a female sex hormone with a steroid structure. Like other steroid horm ones, it binds to specific receptors in the nuclei and regulates gene trans cription (genomic effects). In addition to the genomic effects, it can act as an antioxidant, a process not mediated by the estrogen receptor (nongeno mic effects). Further, estrogen can have a novel action through a specific receptor located in the plasma membrane. In the central nervous system, est rogen provides neuroprotection mediated through multiple mechanisms. In thi s article, we review several possible mechanisms for the neuroprotective ef fects Including antiapoptotic protection by estrogens as transcription fact ors, protection against oxidative stress by estrogens acting as antioxidant s, and neurotrophic cross talk through the signal cascade shared with neuro trophic factors. (C) 2000 Elsevier Science Ltd. All rights reserved.