Schedule of Events | Symposia

Hormonal control of the brain state achieving repetitive challenges over risks

Poster Session B - Sunday, March 30, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Xinyue Hu¹ (xhubi@connect.ust.hk), Yukinori HIRANO¹; ¹The Hong Kong University of Science and Technology

Animals often face conflicts between potential rewards and risks in their environments. Internal states and motivations for reward play a crucial role in shaping risk-taking behaviors, aligning these actions with physiological needs. Although neuromodulatory systems such as dopamine are known to affect attraction and escape, whether risk-taking behavior is determined by specific neural circuits or by broader macro mechanisms influencing the brain state is still unknown. Here we report a macroscale hormonal mechanism adopting the animals' state towards more risk-taking mode. We conducted a choice task where flies had to choose between staying hungry or exploring with electric shocks. While satiated flies showed little risk-taking, starved flies exhibited significant risk-taking, which was not further increased by the presence of food in a new environment. Furthermore, we identify a critical neuropeptide, ecdysis triggering hormone (ETH), whose suppression leads to an increase in risk-taking behavior, and its downstream juvenile hormone (JH) in corpora allata (CA) can affect the behavior directly. We also aimed to utilize an opto-calcium sensor, a technology combining optogenetics, a calcium sensor, and close-proximity labeling, designed to identify specific neurons involved in decision-making, to further investigate the temporal regulation within the neural network. Our finding reveals that hormone levels can influence risk-taking behavior via the ETH-ETHR-JH pathway, while the opto-calcium sensor effectively detects neural activity both in vitro and in vivo. Therefore, our study proposes an idea that a macroscale mechanism through hormones determines the degree of risk-taking behavior, potentially being linked to the local neural circuit activity change.

Topic Area: THINKING: Decision making