Photoacoustic Stimulation with Single-Neuron Precision Developed by a BU Team

By Caroline Amato

An article by a BU team entitled “Non-genetic Photoacoustic Stimulation of Single Neurons” will appear in Light: Science & Applications. This research is led by Professors Chen Yang (ECE, Chem, MSE) and Ji-Xin Cheng (ECE, BME, MSE) in collaboration with Professor John White (BME) and Professor Heng-Ye Man (Biology). The graduate students and researchers who made key contributions to the work include Linli Shi (Chemistry), Ying Jiang (ECE), Fernando Fernandez (BME), Guo Chen (ECE), and Lu Lan (ECE).

Neurostimulation at a high spatial resolution is important in advancing brain circuits’ insights and treating neurological issues. Transcranial-focused ultrasounds have emerged as a non-genetic method to elicit motor responses in animals, such as mice and rabbits. Humans can also show sensory responses through the use of ultrasound stimulation. However, the spatial resolution of conventional piezo-based transducers is limited to several millimeters. New strategies with higher precision are still sought to enable the understanding of mechanical stimulation at the single-cell level and to offer high precision for potential clinical applications.


This team has collaborated to research and develop a tapered fiber optoacoustic emitter (TFOE). The TFOE exploits the optoacoustic effect and generates an acoustic field within a characteristic distance of 40 µm away from the TFOE fiber tip. This allows selective activation of single neurons or smaller cellular structures, such as axons and dendrites. Temporally, the TFOE converts a laser pulse of 3 nanoseconds to a sub-microsecond acoustic pulse. Successful neuron activation is achieved using the generated single acoustic pulse, which is the shortest acoustic stimulus so far for successful neuron activation. Importantly, the near-field ultrasound generated by TFOE allowed optoacoustic stimulation while simultaneously monitoring cell response using the whole-cell patch-clamp recording for the first time. Characterizing these single-cell electrophysiology responses to ultrasound stimuli has been accomplished for the first time and has been difficult to see using conventional ultrasound. These findings show the exciting potential of TFOE as a new technology for non-genetic stimulation of the neural system with high spatial and temporal precision. Many new research opportunities will be opened up by the new capabilities offered by TFOE. 

Professor Chen Yang is associate professor of electrical & computer engineering, materials science & engineering and chemistry at BU. Professor Yang is also associate chair of the ECE master program. She earned her PhD from Harvard University. She received an NSF CAREER Award in 2008. She is a member of the American Chemical Society, Materials Research Society, and Internal Society for Optics and Photonics.

Professor Ji-Xin Cheng is the Moustakas Chair Professor in Photonics and Optoelectronics. He is a professor of biomedical engineering, electrical & computer engineering and materials science & engineering at BU. He earned his PhD from the University of Science and Technology of China in 1998. Cheng received the 2020 Pittsburgh Spectroscopy Award from the Spectroscopy Society of Pittsburgh, the 2019 Ellis R. Lippincott Award jointly from the Optical Society of America, Society for Applied Spectroscopy and Coblentz Society, and the 2015 Craver Award from Coblentz Society. Cheng is also a Fellow of the Optical Society of America and the American Institute of Medicine and Biological Engineering.

Professor John White is a professor and chair of biomedical engineering at BU. He earned his PhD in biomedical engineering from Johns Hopkins University. He is a Fellow of the International Academy of Medical and Biological Engineering and Elected President of the Biomedical Engineering Society. 

Professor Heng-Ye Man is a professor of biology at BU and earned his PhD in Neuroscience from the University of Toronto.