Full 3D dynamic functional ultrasound imaging of neuronal activity in mice

Abstract

Introduction: In vivo neuronal activity imaging is key to understand the mechanisms of complex brain behavior. 2D Functional Ultrasound (fUS) Imaging is a powerful tool for measuring brain activation with high spatiotemporal sampling (80μm, 1 ms) using neurovascular coupling. Here, we demonstrated the proof of concept of in vivo full 3-D fUS and extend the research work toward 3D functional connectivity imaging in mice. Method: A fully programmable 1024-channel ultrasound platform was used to drive 32 x 32 matrix phased arrays (9 MHz central frequency) at ultrafast frame rates (500 volumes per second). Successive plane wave emissions were compounded to produce high sensitivity vascular volumetric images of the brain of anesthetized (Ketamine-Xylazine) and craniotomized mice. Whiskers were alternatively (6 seconds ON/OFF) stimulated during acquisition. Results: High-quality 3D images of cerebral blood volume were obtained and showed the feasibility of task-activated 3D fUS imaging. The activation maps depi...