Stealthy neural recorder: Link neural activity with natural behaviours

We have developed a battery-free, fully implantable, and wireless neural recorder that captures brain nerve signals in primates covertly, aptly named the "Stealthy neural recorder." This device operates undetected by the subjects, allowing it to measure neural activity in a completely natural setting without any behavioural restrictions. The stealthy neural recorder contributes to neuroscientists' observation and analysis of brain function as it naturally occurs, thus enhancing our understanding of neural mechanisms and behaviours.

Stealthy Neural Recorders: Unleashing the Potential of Brain Research in Non-Human Primates

Introduction The brain, our central command centre, manages everything from simple movements to complex cognitive functions. Yet, it is also the origin of debilitating diseases like Alzheimer's, Parkinson’s, epilepsy, and others that afflict millions globally. Advancements in biomedical engineering have opened new avenues for understanding these diseases by studying brain neural activities and their links to physical and psychological states¹.

The Challenge with Traditional Methods Traditionally, brain studies have used rigid, silicon-based neural probes in physically restrained conditions. These setups often involve invasive procedures with the subjects under anaesthesia, connected to bulky machines that process the collected data. This method, while effective in some respects, limits the natural behaviour of the subjects, skewing the data in ways that might not translate well to natural conditions.

The Shift to Minimally Invasive Techniques Recent technological leaps in bioelectronics have brought us flexible neural probes that record neural activity over extended periods without major surgery. These probes are designed from biocompatible materials that mimic the softness of the brain, making them less invasive and more durable. These innovations have significantly reduced the stress on lab animals during experiments, potentially increasing the accuracy of the data collected.

Wireless Technologies: A Game Changer The introduction of wireless power transfer and communication has been a groundbreaking step forward. Devices now can be fully implantable and battery-free, allowing non-human primates (NHPs) to move freely in their environment, mimicking natural behaviours more closely. This has been particularly useful in studies where natural behaviour plays a crucial role in research, like studying instinctive behaviours linked to neurological conditions.

Why NHPs? Non-human primates share many similarities with humans in terms of brain function and social behaviours, making them ideal subjects for neurological studies. However, their larger brain size and freedom of movement present unique challenges. For instance, traditional neural probes and wireless systems struggle to adapt to the varied postures and movements of NHPs, often resulting in loss of signal or data.

Unveiling the Stealthy Neural Recorder: A Game-Changer in Primate Neurobehavioral Studies

Introduction In the realm of neuroscience, accurately monitoring and understanding the intricate behaviours of non-human primates (NHPs) in their natural state has always been a daunting challenge. The introduction of the stealthy neural recorder could solve these challenges in this field, combining state-of-the-art technology with innovative engineering to study instinctive behaviours like eating, all while causing minimal disturbance to the subjects.

Fully integrated Design The stealthy neural recorder is an integrated solution for neuroscience research in primates, seamlessly blending several sophisticated technologies into a compact, efficient device. This neural implant is uniquely designed to be wireless, battery-free, and exceptionally low-power, consuming low power. It's implanted right under the scalp of awake, freely moving NHPs, enabling the capture of deep brain neural signals crucial for analysing complex behaviours.

Key Features and Technological Advances

Flexible Neural Probe with Bioresorbable Shuttle: At about 7.7 cm long, with 32 electrodes, this probe delves into deep brain regions to record neural activity. Its design features a bioresorbable, mechanically transient sucrose insertion shuttle, ensuring minimal damage during insertion and optimal signal clarity.

Wireless Power and Communication: The device includes a built-in wireless power receiver and communication units, eliminating the need for external wires or batteries. This not only enhances the comfort of the NHPs but also allows them to move freely in their environment.

Data Handling and AI Integration: A customized smartphone application interfaces with the recorder, synchronizing and processing the vast amounts of neurobehavioral data collected. Advanced AI algorithms analyse these data to identify patterns linked to specific behaviours, providing unprecedented insights into the neural underpinnings of instinctive actions.

Biomedical Implications The application of this device extends beyond basic research. By allowing for continuous, real-time monitoring without impacting the natural behaviours of NHPs, researchers can glean more accurate insights into neurobehavioral dynamics. This has profound implications for understanding and eventually treating neurodegenerative diseases in humans.

Environmental and Ethical Considerations Designed with ethical considerations in mind, the stealthy neural recorder minimizes both physical and psychological stress on the animals. This approach not only adheres to rigorous animal welfare standards but also improves the quality of the data collected, reflecting more natural behaviour patterns. All experimental procedures described involving animal care and the use of NHPs were approved by the Korea Research Institute of Bioscience and Biotechnology (KRIBB) Institutional Animal Care and Use Committee (KRIBB-AEC-21102). Experimental procedures were performed in accordance with national guidelines and compiled with the Guidelines for the Care and Use of Laboratory Animals.

Conclusion The stealthy neural recorder showed advances in terms of integration in neural interface technology, offering a less invasive, more accurate, and ethically responsible method for studying complex brain activities in non-human primates. As we continue to explore this technology's potential, it may well pave the way for groundbreaking advancements in both animal and human neuroscience.

1. Jeong, J. W. et al. Wireless optofluidic systems for programmable in vivo pharmacology and optogenetics. Cell 162, 662-674 (2015).