Exploring how the brain weighs risk and reward

In the lab of Melissa Warden, associate professor of translational neurosciences at the University of Arizona College of Medicine – Phoenix, researchers study how the brain helps us make split-second decisions, for example, whether to chase a reward or flee from danger. A key focus is the lateral habenula, a brain region that may help animals stop or switch actions when threats arise. 

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Phoenix KEYS intern Shivani Satheeshkumar (she/her) worked with postdoctoral researcher Pamela Miranda to study what happens in the brain when these instincts compete.  

“Young scientists realize they can do these complex things—that it’s really about hard work and curiosity,” said Miranda. “Their fresh eyes help troubleshoot problems we’ve gotten too used to.” 

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To investigate, the team used a validated behavioral model that mimics a natural threat, such as a shadow overhead, to observe decision-making responses in the brain in real time. They then analyzed brain activity to better understand how these responses are processed. 

“My approach to mentorship is all about lighting a spark,” said Warden. “If students understand why their project matters, it’s empowering and hopefully motivating.” 

Satheeshkumar used fluorescent dyes to highlight which brain cells became active during the escape response. Her work will help connect behavior to brain function, a key to understanding how we process threats and rewards in everyday life. 

“At school, we learn about neuroscience, but we never actually get to do it,” said Satheeshkumar. “Now that I’ve held the data in my hands, it has made me even more excited to become a doctor and help address healthcare gaps in my community.”