Integrated ultrasound stimulation and optical imaging of awake mice brain using a transparent ultrasound transducer cranial window

Ultrasound stimulation is a promising non-invasive approach for treating neurological disorders, yet its underlying mechanisms remain poorly understood, limiting clinical translation. While optical imaging can help elucidate these mechanisms, conventional opaque and bulky ultrasound transducers hinder integration with in vivo studies, particularly in awake rodents. To overcome this, we introduce a miniaturized lithium niobate-based transparent ultrasound transducer (TUT) implanted as a thinned-skull cranial window, enabling simultaneous ultrasound stimulation and optical imaging in awake, head-fixed mice. Using laser speckle contrast and intrinsic optical signal imaging, we investigated hemodynamic responses in the somatosensory cortex under various ultrasound stimulation sequences. Our results demonstrate that the TUT cranial window reliably evokes increases in cerebral blood flow and total hemoglobin, with responses scaling with ultrasound intensity and duration. Overall, the TUT cranial window offers an integrated ultrasound stimulation and optical imaging platform for mechanistic studies in awake mice and supports the therapeutic translation of ultrasound neuromodulation.