Chunyang Dong

All Publications

• Unlocking opioid neuropeptide dynamics with genetically encoded biosensors. Nature neuroscience Dong, C., Gowrishankar, R., Jin, Y., He, X. J., Gupta, A., Wang, H., Sayar-Atasoy, N., Flores, R. J., Mahe, K., Tjahjono, N., Liang, R., Marley, A., Or Mizuno, G., Lo, D. K., Sun, Q., Whistler, J. L., Li, B., Gomes, I., Von Zastrow, M., Tejeda, H. A., Atasoy, D., Devi, L. A., Bruchas, M. R., Banghart, M. R., Tian, L. 2024

  Abstract

  Neuropeptides are ubiquitous in the nervous system. Research into neuropeptides has been limited by a lack of experimental tools that allow for the precise dissection of their complex and diverse dynamics in a circuit-specific manner. Opioid peptides modulate pain, reward and aversion and as such have high clinical relevance. To illuminate the spatiotemporal dynamics of endogenous opioid signaling in the brain, we developed a class of genetically encoded fluorescence sensors based on kappa, delta and mu opioid receptors: κLight, δLight and µLight, respectively. We characterized the pharmacological profiles of these sensors in mammalian cells and in dissociated neurons. We used κLight to identify electrical stimulation parameters that trigger endogenous opioid release and the spatiotemporal scale of dynorphin volume transmission in brain slices. Using in vivo fiber photometry in mice, we demonstrated the utility of these sensors in detecting optogenetically driven opioid release and observed differential opioid release dynamics in response to fearful and rewarding conditions.

  View details for DOI 10.1038/s41593-024-01697-1

  View details for PubMedID 39009835

• Prefrontal cortical dynorphin peptidergic transmission constrains threat-driven behavioral and network states. Neuron Wang, H., Flores, R. J., Yarur, H. E., Limoges, A., Bravo-Rivera, H., Casello, S. M., Loomba, N., Enriquez-Traba, J., Arenivar, M., Wang, Q., Ganley, R., Ramakrishnan, C., Fenno, L. E., Kim, Y., Deisseroth, K., Or, G., Dong, C., Hoon, M. A., Tian, L., Tejeda, H. A. 2024

  Abstract

  Prefrontal cortical (PFC) circuits provide top-down control of threat reactivity. This includes ventromedial PFC (vmPFC) circuitry, which plays a role in suppressing fear-related behavioral states. Dynorphin (Dyn) has been implicated in mediating negative affect and maladaptive behaviors induced by severe threats and is expressed in limbic circuits, including the vmPFC. However, there is a critical knowledge gap in our understanding of how vmPFC Dyn-expressing neurons and Dyn transmission detect threats and regulate expression of defensive behaviors. Here, we demonstrate that Dyn cells are broadly activated by threats and release Dyn locally in the vmPFC to limit passive defensive behaviors. We further demonstrate that vmPFC Dyn-mediated signaling promotes a switch of vmPFC networks to a fear-related state. In conclusion, we reveal a previously unknown role of vmPFC Dyn neurons and Dyn neuropeptidergic transmission in suppressing defensive behaviors in response to threats via state-driven changes in vmPFC networks.

  View details for DOI 10.1016/j.neuron.2024.03.015

  View details for PubMedID 38614102

• Opioidergic signaling contributes to food-mediated suppression of AgRP neurons. Cell reports Sayar-Atasoy, N., Yavuz, Y., Laule, C., Dong, C., Kim, H., Rysted, J., Flippo, K., Davis, D., Aklan, I., Yilmaz, B., Tian, L., Atasoy, D. 2024; 43 (1): 113630

  Abstract

  Opioids are generally known to promote hedonic food consumption. Although much of the existing evidence is primarily based on studies of the mesolimbic pathway, endogenous opioids and their receptors are widely expressed in hypothalamic appetite circuits as well; however, their role in homeostatic feeding remains unclear. Using a fluorescent opioid sensor, deltaLight, here we report that mediobasal hypothalamic opioid levels increase by feeding, which directly and indirectly inhibits agouti-related protein (AgRP)-expressing neurons through the μ-opioid receptor (MOR). AgRP-specific MOR expression increases by energy surfeit and contributes to opioid-induced suppression of appetite. Conversely, its antagonists diminish suppression of AgRP neuron activity by food and satiety hormones. Mice with AgRP neuron-specific ablation of MOR expression have increased fat preference without increased motivation. These results suggest that post-ingestion release of endogenous opioids contributes to AgRP neuron inhibition to shape food choice through MOR signaling.

  View details for DOI 10.1016/j.celrep.2023.113630

  View details for PubMedID 38165803

• Psychedelics promote neuroplasticity through the activation of intracellular 5-HT2A receptors SCIENCE Vargas, M. V., Dunlap, L. E., Dong, C., Carter, S. J., Tombari, R. J., Jami, S. A., Cameron, L. P., Patel, S. D., Hennessey, J. J., Saeger, H. N., McCorvy, J. D., Gray, J. A., Tian, L., Olson, D. E. 2023; 379 (6633): 700-706

  Abstract

  Decreased dendritic spine density in the cortex is a hallmark of several neuropsychiatric diseases, and the ability to promote cortical neuron growth has been hypothesized to underlie the rapid and sustained therapeutic effects of psychedelics. Activation of 5-hydroxytryptamine (serotonin) 2A receptors (5-HT2ARs) is essential for psychedelic-induced cortical plasticity, but it is currently unclear why some 5-HT2AR agonists promote neuroplasticity, whereas others do not. We used molecular and genetic tools to demonstrate that intracellular 5-HT2ARs mediate the plasticity-promoting properties of psychedelics; these results explain why serotonin does not engage similar plasticity mechanisms. This work emphasizes the role of location bias in 5-HT2AR signaling, identifies intracellular 5-HT2ARs as a therapeutic target, and raises the intriguing possibility that serotonin might not be the endogenous ligand for intracellular 5-HT2ARs in the cortex.

  View details for DOI 10.1126/science.adf0435

  View details for Web of Science ID 000994361400002

  View details for PubMedID 36795823

  View details for PubMedCentralID PMC10108900

• Fluorescence Imaging of Neural Activity, Neurochemical Dynamics, and Drug-Specific Receptor Conformation with Genetically Encoded Sensors ANNUAL REVIEW OF NEUROSCIENCE Dong, C., Zheng, Y., Long-Iyer, K., Wright, E. C., Li, Y., Tian, L. 2022; 45: 273-294

  Abstract

  Recent advances in fluorescence imaging permit large-scale recording of neural activity and dynamics of neurochemical release with unprecedented resolution in behaving animals. Calcium imaging with highly optimized genetically encoded indicators provides a mesoscopic view of neural activity from genetically defined populations at cellular and subcellular resolutions. Rigorously improved voltage sensors and microscopy allow for robust spike imaging of populational neurons in various brain regions. In addition, recent protein engineering efforts in the past few years have led to the development of sensors for neurotransmitters and neuromodulators. Here, we discuss the development and applications of these genetically encoded fluorescent indicators in reporting neural activity in response to various behaviors in different biological systems as well as in drug discovery. We also report a simple model to guide sensor selection and optimization.

  View details for DOI 10.1146/annurev-neuro-110520-031137

  View details for Web of Science ID 000826690800013

  View details for PubMedID 35316611

  View details for PubMedCentralID PMC9940643

• Psychedelic-inspired drug discovery using an engineered biosensor CELL Dong, C., Ly, C., Dunlap, L. E., Vargas, M. V., Sun, J., Hwang, I., Azinfar, A., Oh, W., Wetsel, W. C., Olson, D. E., Tian, L. 2021; 184 (10): 2779-+

  Abstract

  Ligands can induce G protein-coupled receptors (GPCRs) to adopt a myriad of conformations, many of which play critical roles in determining the activation of specific signaling cascades associated with distinct functional and behavioral consequences. For example, the 5-hydroxytryptamine 2A receptor (5-HT2AR) is the target of classic hallucinogens, atypical antipsychotics, and psychoplastogens. However, currently available methods are inadequate for directly assessing 5-HT2AR conformation both in vitro and in vivo. Here, we developed psychLight, a genetically encoded fluorescent sensor based on the 5-HT2AR structure. PsychLight detects behaviorally relevant serotonin release and correctly predicts the hallucinogenic behavioral effects of structurally similar 5-HT2AR ligands. We further used psychLight to identify a non-hallucinogenic psychedelic analog, which produced rapid-onset and long-lasting antidepressant-like effects after a single administration. The advent of psychLight will enable in vivo detection of serotonin dynamics, early identification of designer drugs of abuse, and the development of 5-HT2AR-dependent non-hallucinogenic therapeutics.

  View details for DOI 10.1016/j.cell.2021.03.043

  View details for Web of Science ID 000652830800019

  View details for PubMedID 33915107

  View details for PubMedCentralID PMC8122087

• Directed Evolution of a Selective and Sensitive Serotonin Sensor via Machine Learning CELL Unger, E. K., Keller, J. P., Altermatt, M., Liang, R., Matsui, A., Dong, C., Hon, O. J., Yao, Z., Sun, J., Banala, S., Flanigan, M. E., Jaffe, D. A., Hartanto, S., Carlen, J., Mizuno, G. O., Borden, P. M., Shivange, A., Cameron, L. P., Sinning, S., Underhill, S. M., Olson, D. E., Amara, S. G., Lang, D., Rudnick, G., Marvin, J. S., Lavis, L. D., Lester, H. A., Alvarez, V. A., Fisher, A. J., Prescher, J. A., Kash, T. L., Yarov-Yarovoy, V., Gradinaru, V., Looger, L. L., Tian, L. 2020; 183 (7): 1986-+

  Abstract

  Serotonin plays a central role in cognition and is the target of most pharmaceuticals for psychiatric disorders. Existing drugs have limited efficacy; creation of improved versions will require better understanding of serotonergic circuitry, which has been hampered by our inability to monitor serotonin release and transport with high spatial and temporal resolution. We developed and applied a binding-pocket redesign strategy, guided by machine learning, to create a high-performance, soluble, fluorescent serotonin sensor (iSeroSnFR), enabling optical detection of millisecond-scale serotonin transients. We demonstrate that iSeroSnFR can be used to detect serotonin release in freely behaving mice during fear conditioning, social interaction, and sleep/wake transitions. We also developed a robust assay of serotonin transporter function and modulation by drugs. We expect that both machine-learning-guided binding-pocket redesign and iSeroSnFR will have broad utility for the development of other sensors and in vitro and in vivo serotonin detection, respectively.

  View details for DOI 10.1016/j.cell.2020.11.040

  View details for Web of Science ID 000602900800018

  View details for PubMedID 33333022

  View details for PubMedCentralID PMC8025677

• An expanded palette of dopamine sensors for multiplex imaging in vivo NATURE METHODS Patriarchi, T., Mohebi, A., Sun, J., Marley, A., Liang, R., Dong, C., Puhger, K., Mizuno, G., Davis, C. M., Wiltgen, B., von Zastrow, M., Berke, J. D., Tian, L. 2020; 17 (11): 1147-+

  Abstract

  Genetically encoded dopamine sensors based on green fluorescent protein (GFP) enable high-resolution imaging of dopamine dynamics in behaving animals. However, these GFP-based variants cannot be readily combined with commonly used optical sensors and actuators, due to spectral overlap. We therefore engineered red-shifted variants of dopamine sensors called RdLight1, based on mApple. RdLight1 can be combined with GFP-based sensors with minimal interference and shows high photostability, permitting prolonged continuous imaging. We demonstrate the utility of RdLight1 for receptor-specific pharmacological analysis in cell culture, simultaneous assessment of dopamine release and cell-type-specific neuronal activity and simultaneous subsecond monitoring of multiple neurotransmitters in freely behaving rats. Dual-color photometry revealed that dopamine release in the nucleus accumbens evoked by reward-predictive cues is accompanied by a rapid suppression of glutamate release. By enabling multiplexed imaging of dopamine with other circuit components in vivo, RdLight1 opens avenues for understanding many aspects of dopamine biology.

  View details for DOI 10.1038/s41592-020-0936-3

  View details for Web of Science ID 000566893800001

  View details for PubMedID 32895537

  View details for PubMedCentralID PMC8169200