On the Neuromodulatory Pathways of the In Vivo Brain by Means of Transcranial Focused Ultrasound.

For last decade, low-intensity transcranial focused ultrasound (tFUS) has been rapidly developed for a myriad of successful applications in neuromodulation. tFUS possesses high spatial resolution, focality and depth penetration as a noninvasive neuromodulation tool. Despite the promise, confounding activation can be observed in rodents when stimulation parameters are not selected carefully. Here we summarize the existing classes of observations for ultrasound neuromodulation: ultrasound directly activates a localized area, or ultrasound indirectly activates auditory pathways, which further propagates to other cortical networks. We also present control in vivo animal studies, which suggest that underlying tFUS brain modulation is characterized by localized activation independent of auditory networks activations.