title: Focused ultrasound neuromodulation of cortical and subcortical brain structures using 1.9 MHz.
abstract: OBJECTIVE
  Ultrasound neuromodulation is a promising noninvasive technique for controlling neural activity. Previous small animal studies suffered from low targeting specificity because of the low ultrasound frequencies (<690 kHz) used. In this study, the authors demonstrated the capability of focused ultrasound (FUS) neuromodulation in the megahertz-range to achieve superior targeting specificity in the murine brain as well as demonstrate modulation of both motor and sensory responses.
  
  
  METHODS
  FUS sonications were carried out at 1.9 MHz with 50% duty cycle, pulse repetition frequency of 1 kHz, and duration of 1 s. The robustness of the FUS neuromodulation was assessed first in sensorimotor cortex, where elicited motor activities were observed and recorded on videos and electromyography. Deeper brain regions were then targeted where pupillary dilation served as an indicative of successful modulation of subcortical brain structures.
  
  
  RESULTS
  Contralateral and ipsilateral movements of the hind limbs were repeatedly observed when the FUS was targeted at the sensorimotor cortex. Induced trunk and tail movements were also observed at different coordinates inside the sensorimotor cortex. At deeper targeted-structures, FUS induced eyeball movements (superior colliculus) and pupillary dilation (pretectal nucleus, locus coeruleus, and hippocampus). Histological analysis revealed no tissue damage associated with the FUS sonications.
  
  
  CONCLUSIONS
  The motor movements and pupillary dilation observed in this study demonstrate the capability of FUS to modulate cortical and subcortical brain structures without inducing any damage. The variety of responses observed here demonstrates the capability of FUS to perform functional brain mapping.
authors: Department of Biomedical Engineering, Columbia University, New York, New York 10027 and Department of Physics, FFCLRP, University of São Paulo, Ribeirão Preto, SP 14040-901, Brazil.
authors: Hermes A S
authors: HA
authors: Kamimura
authors: Department of Biomedical Engineering, Columbia University, New York, New York 10027.
authors: Shutao
authors: S
authors: Wang
authors: Department of Biomedical Engineering, Columbia University, New York, New York 10027.
authors: Hong
authors: H
authors: Chen
authors: Department of Biomedical Engineering, Columbia University, New York, New York 10027.
authors: Qi
authors: Q
authors: Wang
authors: Department of Biomedical Engineering, Columbia University, New York, New York 10027.
authors: Christian
authors: C
authors: Aurup
authors: Department of Biomedical Engineering, Columbia University, New York, New York 10027.
authors: Camilo
authors: C
authors: Acosta
authors: Department of Physics, FFCLRP, University of São Paulo, Ribeirão Preto, SP 14040-901, Brazil.
authors: Antonio A O
authors: AA
authors: Carneiro
authors: Department of Biomedical Engineering, Columbia University, New York, New York 10027 and Department of Radiology, Columbia University, New York, New York 10032.
authors: Elisa E
authors: EE
authors: Konofagou
mesh_terms: D001921:Brain / Q000502:physiology*; D006801:Humans; D014464:Ultrasonic Therapy / Q000379:methods*