Sex hormones play an important role in shaping animal behavior, and their role began very early Hormonal surges early in life help shape the developing brain and establish circuits that will affect behavior throughout life. Hundreds of genes in the brain are controlled by estrogen. In addition to early shaping of developing neural circuits, fluctuations in hormone levels can lead to changes in mood, energy balance and behavior throughout life. These effects occur when activated estrogen receptors are located directly on the cell's DNA to turn genes on or off.
Jessica tollkuhn, associate professor of Cold Spring Harbor Laboratory, graduate student Bruno gegenhuber and their colleagues have been mapping the exact location of estrogen receptor locking DNA in mouse brain cells. They studied male and female mice and compared the brains of adult mice with those of young mice that were still developing. Published in [Nature] on May 4( https://www.nature.com/articles/s41586-022-04686-1 ) 》In a study in the journal, they reported on the targets of hormone receptors in the brain and showed that estrogen forms physical differences between male and female brain development.
Tollkuhn explained that estrogen exists in both male and female brains: some neurons make their own from testosterone. In male mice, estrogen produced by a surge of testosterone released shortly after birth shapes the developing circuit. Therefore, some brain regions of male mice are larger and contain more cells than those of female mice - this difference affects a range of behaviors in adulthood, including mating, parenting and aggression.
"In the critical period of brain development and wiring, it must obtain this input to make these permanent changes in brain wiring. This is a short surge, but it seems to have an extremely lasting impact on brain development."
Tollkuhn's team studied the foothold of estrogen receptors after this hormone surge, focusing on a brain region called BNST, which is larger in males than females in mice and humans. They found that many genes involved in the development of neurons are controlled by estrogen, including a series of genes. Although estrogen itself stays in the brain for only a few hours, it seems that hormone controlled genes remain active for a few weeks.
Now that they know the target genes of estrogen in the brain, tollkuhn's team plans to explore how these genes mediate the different effects of hormones on brain development, behavior and disease.