The Su lab uses Drosophila to ask: how does the nervous system efficiently extract and utilize sensory information in dynamic environments to guide behavior? The lab focuses on early olfactory processing and how neuromodulators shape sensory neuron activity to influence downstream circuits and behavior. Since subtle changes at the sensory input stage can profoundly affect circuits and behavior, we study "input-layer computations" to reveal principles of efficient neural processing and inspire strategies for data science. Our work integrates genetics, electrophysiology, calcium imaging, behavior, and EM across molecular, cellular, and circuit levels.

Our research has elucidated two fundamental mechanisms that shape olfactory information processing at the periphery: neuromodulation and ephaptic coupling.

First, we discovered that odor responses in Drosophila olfactory receptor neurons (ORNs) are subject to complex, state-dependent regulation. We have identified multiple physiological contexts—including sex, age, social isolation, mating status, dietary nutrients, and circadian information—that modulate ORN activity related to courtship and mating behavior. Mechanistically, we found that the DEG/ENaC channel Pickpocket 25 (PPK25) functions as a calcium-activated transduction channel that amplifies olfactory signals downstream of ionotropic olfactory receptors selectively in males. Its sexually dimorphic expression in courtship-promoting ORNs is controlled by specific FruM isoforms. In addition, in females, we discovered that juvenile hormone desensitizes Or47b responses in mated females, which enhances mate selectivity and increases female reproductive fitness.

Second, we established the Drosophila olfactory system as a genetically tractable model for studying ephaptic interactions—direct electrical communication between ORNs housed within the same sensillum (sensory hair). We demonstrated that these non-synaptic circuit interactions are robust and widespread across multiple sensillum types. By integrating ultrastructural EM morphometric data with electrophysiological and behavioral analyses, we further showed that genetically predetermined morphological differences between compartmentalized ORNs underlie their functional asymmetry. This asymmetry, in turn, drives the most robust behavioral responses to odor mixtures of specific ratios. Importantly, we provided evidence that ephaptic coupling alone is sufficient to modulate behavioral responses to odor mixtures.

Collectively, our findings reveal that sophisticated olfactory processing begins at the periphery through both neuromodulation and electrical ephaptic communication, offering insights into fundamental principles of inter-neuronal signaling that may extend to other sensory systems.

2016 Faculty Mentorship Award, Division of Biological Sciences, UCSD

2015 Ray Thomas Edwards Foundation Career Award

2015 Hellman Fellowship

2013 AChemS ECRO Fellowship, Association for Chemoreception Sciences  

2006 Phi Beta Kappa Society, Johns Hopkins University

2006 Young Investigator Award, Johns Hopkins University School of Medicine

(*corresponding author)

1. Intrinsic diversity in odor-evoked calcium rises across Drosophila olfactory neurons. Yiyi Xiao, Shiuan-Tze Wu, Renny Ng and Chih-Ying Su*. Journal of Neuroscience. 2026, 46(18), e2132252026. 

2. Morphological specializations of mosquito CO2-sensing olfactory receptor neurons. Shadi Charara^#, Jonathan Choy^#, Kalyani Cauwenberghs, Pawel Vijayakumar, Renny Ng, Keun-Young Kim, Shih-Che Weng, Omar S Akbari, Mark H Ellisman, Scott A Rifkin and Chih-Ying Su*. Proceedings of the National Academy of Sciences of the United States of America. 2025, 122 (43), e2514666122.

3. Peripheral preprocessing in Drosophila facilitates odor classification. Palka Puri, Shiuan-Tze Wu, Chih-Ying Su, and Johnatan Aljadeff*. Proceedings of the National Academy of Sciences of the United States of America. 2024, 121(21), e2316799121.

4. Valence opponency in peripheral olfactory processing. Shiuan-Tze Wu^#, Jen-Yung Chen^#, Vanessa Martin, Renny Ng, Ye Zhang, Dhruv Grover, Ralph J Greenspan, Johnatan Aljadeff and Chih-Ying Su*. Proceedings of the National Academy of Sciences of the United States of America. 2022, 119(5), e2120134119.

5. Systematic morphological and morphometric analysis of identified olfactory receptor neurons in Drosophila melanogaster. Cesar Nava Gonzales^#, Quintyn McKaughan^#, Eric A Bushong, Kalyani Cauwenberghs, Renny Ng, Matthew Madany, Mark H Ellisman and Chih-Ying Su*. Elife. 2021, 10, e69896.

6. Amplification of Drosophila olfactory responses by a DEG/ENaC channel. Renny Ng, Secilia S Salem, Shiuan-Tze Wu, Meilin Wu, Hui-Hao Lin, Andrew K Shepherd, William J Joiner, Jing W Wang and Chih-Ying Su*. Neuron. 2019, 104(5), 947-959.

7. Asymmetric ephaptic inhibition between compartmentalized olfactory receptor neurons. Ye Zhang^#, Tin Ki Tsang^#, Eric A Bushong, Li-An Chu, Ann-Shyn Chiang, Mark H Ellisman, Jürgen Reingruber and Chih-Ying Su*. Nature Communications. 2019, 10(1), 1-16.

8. Hormonal modulation of pheromone detection enhances male courtship success. Hui-Hao Lin^#, De-Shou Cao^#, Sachin Sethi, Zheng Zeng, Jacqueline SR Chin, Tuhin Subhra Chakraborty, Andrew K Shepherd, Christine A Nguyen, Joanne Y Yew, Chih-Ying Su*, Jing W Wang*. Neuron. 2016, 90(6),1272-1285.

9. Non-synaptic inhibition between grouped neurons in an olfactory circuit. Chih-Ying Su, Karen Menuz, Johannes Reisert, John R Carlson*. Nature. 2012, 492(7427), 66-71.

10. Olfactory perception: receptors, cells, and circuits. Chih-Ying Su^#, Karen Menuz^#, John R Carlson*. Cell. 2009, 139(1), 45-59.

https://smart.org.cn/career/research-lab/1199.html