Hormones are chemicals in the body that help control many functions, including mood and energy. They also affect the brain, changing emotions, energy levels, and how people make decisions. However, experts have not fully understood these effects. A recent study by researchers led by New York University’s Center for Neural Science explores how estrogen, a main female hormone involved in reproduction, impacts learning and decision-making. The research used lab rats to observe brain changes over the female reproductive cycle, a regular process where hormone levels rise and fall to prepare for possible pregnancy.
The study found that learning abilities naturally change during this cycle because of hidden molecular shifts related to dopamine. Dopamine is a brain chemical that sends reward signals, helping the brain learn from positive experiences. In experiments, rats learned to connect audio sounds with rewards, like getting water. When estrogen levels were high, the rats learned faster because estrogen increased dopamine activity in the brain's reward area, making those signals stronger.
Effects on learning and potential links to disorders
By contrast, when estrogen was low or blocked, dopamine signals weakened, and learning slowed down. This did not affect decision-making overall; the changes were specific to how well the rats could learn new things. The findings suggest a reason why some mental health issues, like psychiatric disorders which involve problems with mood or thinking, might worsen with hormone changes. These disorders often show varying symptoms tied to hormone levels, and better knowledge of estrogen's role could help explain their causes.
The research highlights estrogen's broad influence on brain function and points to possible biological links between hormones, learning, and disease. This work aims to improve understanding of both normal brain activity and conditions like depression or anxiety.
The researchers have described the methods and results of this study in a paper published in Nature Neuroscience.