No, that鈥檚 not a bird鈥檚-eye view of the Earth at night. Those glowing green lines connecting each dot aren鈥檛 highways. And the big dots aren鈥檛 cities or towns either. But there are power lines and, in a way, it is still a map. What you鈥檙e looking at is a close-up view of neural circuits deep inside a region of the brain called the hypothalamus. The image comes to us from the lab of 黑料吃瓜资源 Associate Professor Jessica Tollkuhn.
The hypothalamus is the almond-sized control center of the brain. It keeps the body in a stable state called homeostasis. It does this by coordinating involuntary functions like body temperature, heart rate, and even sex drive. The hypothalamus also releases hormones to trigger processes like muscle and bone growth, ovulation, and sperm production. But this isn鈥檛 a one-way street. Hormones from other parts of the body have their own effects on the brain as well.
The sex hormones estrogen and testosterone play essential roles during early brain development. They shape neural circuitry, the 鈥減ower lines鈥� seen above, helping to define brain sex differences soon after birth. Estrogen in particular helps set the stage for energy balance, mood, and behavior throughout life. However, levels of these hormones naturally decrease over time. This has been linked to cognitive decline and age-related neurodegenerative diseases like Alzheimer鈥檚 and Parkinson鈥檚.
In 2022, Tollkuhn and her team discovered the genes in mice that estrogen targets during early development. Both male and female brains contain estrogen. But in males, it鈥檚 generated by a surge of testosterone that causes certain regions of the brain to grow larger and contain more cells than in females. This difference affects various behaviors in adulthood like mating, parenting, and aggression.
Tollkuhn and her team are now working to identify the genes testosterone regulates in the brain. And they鈥檙e tracking the roles of hormone-regulated genes later in life. Their work could lead to better hormone replacement therapies and new strategies to protect against age-related neurodegenerative diseases.
Written by: Nick Wurm, Communications Specialist | [email protected] | 516-367-5940
About
Jessica Tollkuhn
Associate Professor
Cancer Center Member
Ph.D., University of California, San Diego, 2006