Fiber-optic photoacoustic enables targeted neuromodulation and stress reduction in mice

Ultrasound neuromodulation offers a non-invasive approach to modulate neural activity in the central nervous system. Precise, minimally invasive devices capable of targeted stimulation remain limited. A 200 µm diameter fiber-optic photoacoustic emitter (FPE) was developed, coated with a MXene (Ti₃C₂T_x) and polydimethylsiloxane composite to generate controllable, broadband ultrasonic waves with high spatial precision. Using this FPE to stimulate the medial prefrontal cortex in mice, it was observed marked alleviation of acute social defeat stress-induced emotional stress, evidenced by reduced anxiety-like behavior and increased social interaction. This approach enables near-field, broadband, and tunable ultrasound neuromodulation with potential applications in treating neuropsychiatric disorders involving emotional regulation.