Hansol Lim and Mekhla Rudra win Young Scientist Award

Annual award presented for outstanding publications by early-career researchers

To the point:

• Young scientists honored: Hansol Lim and Mekhla Rudra receive this year’s Young Scientist Award, which recognizes outstanding publications by young scientists at the Institute.
• Decoding the brain’s emotional signals: Lim’s study showed brain circuits for fear, reward, and social behavior are more interconnected than thought, which may give insights into why emotions can be both universal and uniquely personal.
• Revealing new insights into sexual development in birds: Rudra’s research found that the androgen receptor, which works by binding to testosterone, commonly known as the “male sex hormone”, actually plays a critical role in both male and female bird development.

The Max Planck Institute for Biological Intelligence is delighted to announce that Mekhla Rudra and Hansol Lim have won the Institute’s Young Scientist Award this year. The €1000 prize recognizes early-career researchers with outstanding published studies based on work carried out at the Institute and celebrates the vital role of early-career scientists in advancing science.

This year’s award highlights discoveries that uncover new dimensions on how the sex hormone testosterone shapes development in male and female birds, and reveal that brain circuits involved in emotional and social behavior are more interconnected than previously thought. The findings shed new light on how biology shapes development and behavior and opens exciting directions for future research.

Decoding mixed signals in the brain

Hansol Lim earned her master’s degree at the Max Planck Institute for Brain Research in Frankfurt before joining the Molecules - Signaling – Development Department led by Rüdiger Klein at the Max Planck Institute for Biological Intelligence, where she completed her PhD focused on how brain circuits regulate emotion, social behavior, and appetite. She is now a postdoctoral researcher at Stanford University.

Lim’s research, published in Nature Communications, explored how neurons in the basolateral amygdala – a region involved in processing emotions – contribute to behaviors such as feeding, fear responses, and social interaction. Working with colleagues at the Max Planck Institute for Biological Intelligence and Ludwig Maximilian University of Munich, the study mapped distinct neuron groups in the mouse brain and explored how they responded to different types of sensory input.

The study showed that genetically distinct neurons not only cluster together in the brain but also carry out specific functions as a group – those that “wire together” and “sit together” often “work together”. Interestingly, within these structured groups, some neurons displayed ‘mixed selectivity’: they responded to both social and fear-related cues.

“This highlights a fundamental idea: while many aspects of our brain are genetically ‘hard-wired’, the subjective nature of emotion may stem from this internal crosstalk and might explain why emotions can be both universal and deeply personal at the same time,” says Lim.

“My current work builds on these insights, looking at how these brain circuits can become disrupted, for example after drug exposure, and how that might drive behaviors like addiction. There’s still so much we don’t know, and that’s what fascinates me and keeps me curious. The Max Planck Institute still feels like my scientific home and it’s incredible to receive this award: I’m especially grateful to the mentors, colleagues, and collaborators who supported me throughout my PhD.”

Rethinking testosterone: a key hormone in both male and female development

Mekhla Rudra is a doctoral researcher in the Department of Behavioral Neurobiology, led by Manfred Gahr at the Max Planck Institute for Biological Intelligence, where she studies how hormones influence social behaviors and development in birds. She completed her bachelor’s and master’s degrees in zoology at Presidency University in Kolkata, India.

In collaboration with the Technical University of Munich, Rudra and her colleagues used the CRISPR-Cas9 gene editing technique in domestic chickens to “switch off” the androgen receptor – a protein that testosterone binds to in order to elicit its functions in cells. This allowed them to answer specific questions concerning the involvement of the androgen receptor in avian sexual development.

When the androgen receptor was disabled, key features such as the rooster’s comb and egg-laying in hens failed to develop. Yet other characteristic “male” traits, like spurs and elongated tail feathers, still appeared in male birds. The study, also published in Nature Communications, showed for the first time that testosterone, by binding to the androgen receptor, plays a crucial role in both males and females and challenges the idea of testosterone as purely a “male hormone”.

“This study pushes the boundaries of our knowledge on how a hormone as crucial as testosterone functions,” says Rudra. “Although the role of testosterone in the appearance, physiology and behavior of birds has been extensively studied, our study sheds light on how these aspects are influenced by the complex interplay of the hormone with its receptor.”

“Being at the MPI and based at the beautiful Seewiesen site provided me with the most perfect environment to carry out my research – both picturesque and intellectually stimulating,” she adds. “I’m grateful to my colleagues and collaborators for their continued support and especially to my supervisor, Manfred, for his brilliant mentorship over the years. In an institute where everyone is engaged in such great research, I am incredibly honored to receive this award on behalf of the entire team.”