Question

Male mammals have more circulating testosterone than they do circulating estrogens; however, the brain is “masculinized” by estradiol (an estrogen). Briefly describe how this takes place, and why female brains aren’t masculinized.

Answer 1

Estrogen Plays Key Role in Male Brain Development. Not testosterone, but rather estrogen, the “female” hormone, is most directly responsible for the development of brain circuits in males that guide aggressive and territorial behaviors – at least in mice.Circulating testosterone activates the androgen receptor (AR) and is also converted into estrogen in the brain via aromatase. This conversion is the primary source of estrogen to the male brain. It is unclear whether testosterone and estrogen signaling interact to masculinize neural circuits.In the central nervous system, estrogen has been shown to increase cerebral blood flow, provide anti-inflammatory effects, promote neuronal synapse activity and to exert both neuroprotective and neurotrophic effects on tissues in the brain.Hot flashes often happen during menopause due to low estrogen levels. Depression: Estrogen is thought to increase serotonin, which is a chemical in the brain that boosts mood. Estrogen deficiency may cause a decline in serotonin that contributes to mood swings or depression.