Brain-implanted conductors amplify radiofrequency fields in rodents: Advantages and risks

Area of Science:

• Biophysics
• Neuroscience
• Biomedical Engineering

Background:

• Increasing daily exposure to radiofrequency (RF) fields from wireless and medical technologies.
• Potential for RF energy to cause tissue heating and injury, especially with implanted devices.
• Need to understand RF-tissue interactions with implants for safety protocols and medical device use.

Purpose of the Study:

• To investigate the neurological effects of RF exposure in rodents with neuronal recording electrodes.
• To assess RF energy interactions with brain tissue and implanted devices.
• To determine the impact of RF exposure on brain activity, temperature, and behavior.

Main Methods:

• Exposure of freely moving and anesthetized rats and mice to 950 MHz RF energy.
• Monitoring of brain activity, temperature, and behavior during RF exposure.
• Utilizing an optical temperature measurement system to assess brain temperature changes near implants.

Main Results:

• RF exposure induced fast onset firing of single neurons without causing heat injury.
• Brain implants amplified RF stimulation effects, leading to reversible behavioral changes.
• A tenfold increase in brain temperature was observed near the implant during RF exposure.

Conclusions:

• Results highlight the importance of safety assessments for brain-implanted devices.
• Metal implants may be viable for neurostimulation if brain temperature is managed within safe limits.
• Understanding RF-tissue-implant interactions is crucial for developing safe and effective wireless technologies and medical devices.