Wearable Transcranial Ultrasound System for Remote Stimulation of Freely Moving Animal

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Devices

Background:

• Transcranial focused ultrasound (tFUS) is a noninvasive brain stimulation technique with significant potential in neuroscience.
• Current methods often rely on anesthetized or immobilized animal models, limiting behavioral studies and treatment applications.
• There is a need for systems that allow tFUS in freely behaving subjects to better understand brain function and therapeutic effects.

Purpose of the Study:

• To develop and validate a wireless, wearable system for transcranial focused ultrasound (tFUS) brain stimulation in freely behaving animals.
• To assess the system's capability to modulate brain activity and its potential for therapeutic applications, such as stroke rehabilitation.
• To provide a platform for more naturalistic investigation of tFUS effects on behavior and long-term brain changes.

Main Methods:

• A wearable tFUS system was engineered using a microcontroller and amplifier circuit, featuring a custom PZT transducer.
• Near-infrared spectroscopy (NIRS) was employed to monitor brain activity via induced hemodynamic changes.
• The system's safety and efficacy were evaluated in a rat stroke model (tMCAO), including temperature monitoring and histological analysis.

Main Results:

• The lightweight (20 g) wearable device enabled full range of motion in freely behaving rats.
• tFUS stimulation induced measurable hemodynamic changes in the targeted brain areas.
• Five days of tFUS post-stroke facilitated behavioral recovery in open-field tests, with no adverse effects noted even after 40-minute sonication.

Conclusions:

• The developed wireless, wearable tFUS system is effective for brain stimulation in freely moving rats.
• The system demonstrates the potential for both short- and long-term modulation of brain activity.
• This technology offers a more naturalistic environment for behavioral and long-term studies of tFUS, advancing neuroscience research and therapeutic development.