The spinal cord is more difficult to access and study than the brain. The challenges posed by its mobility and anatomy make it difficult to understand exactly how it works.
Rice University engineers will work with collaborators to optimize a series of nanoelectronic threads, or NETs, already successfully used to collect high-fidelity, long-term data from neurons in the brain. is. $6.25 million, 4 annual grant from the National Institutes of Health for use in the spine.
In addition to recording neuronal activity, NET probes can provide tunable local stimulation to neighboring neurons. Rice’s neuroengineers also hope to maximize the functional bandwidth of NETs by integrating them into larger data processing systems.
This new tool could help neuroscientists unlock the secrets of spinal cord function and bring new hope to patients dealing with injuries and other related medical conditions.
So far, how neurons in the spinal cord actually function is poorly understood. For example, when you move your arm or walk around, you have an intention in your brain and your muscles follow it. The translation of this initial intention into the specific movements of each muscle is manipulated and carried out in the spinal cord, a circuit made up of thousands of neurons to perform this job. But I’m not exactly sure how this is achieved. “
Chong Xie, Principal Investigator of the Grant, Associate Professor of Electrical Engineering, Computer Engineering and Neuroengineering
By using electrodes to track neuronal activity in the brain, neuroscientists have been able to learn a lot about how the brain functions. The flexible NET probes developed by Xie and co-workers integrate seamlessly with brain tissue and outperform rigid probes when used to record electrical information from individual neurons in the brain. Demonstrate.
Preliminary tests have shown that NET probes can achieve high-quality, long-term recordings from mouse spinal cord neurons. However, scientists intend to further adapt NETs to the specific structural and functional needs of the spinal cord.
In the brain, the distribution of neurons, or bundles of nerve fibers known as gray and white matter, is exactly the opposite of the anatomy of the spinal cord.
“We usually call this the ‘inside-out anatomy’ of the spinal cord,” said Lan Ruan, assistant professor of electrical and computer engineering and co-investigator of the grant. . “The outer layer of the brain (the gray matter) contains neurons, and inside it lies fibers called white matter. In the spinal cord, the white matter, or fibers, are on the outside and protect the neurons. neurons are even more difficult to access.”
To ensure better access, the scientists determined that the spinal cord was large enough to be implanted at various sites in the spine, yet large enough to cover a deeper reach and capture data from neurons in cross-sections of the spinal cord. I am planning to develop a probe design with a channel
Another goal is to equip the probe with stimulation capabilities in addition to recording capabilities.
“This electrode can do both,” Ruan said. “For patients with spinal cord injuries and other types of injury, this has direct implications for health, as stimulation can be a way to restore fine motor control. There are some very successful techniques that demonstrate that motion can be restored, but to affect finer motor control, we need to get inside the code and have greater access and precision to apply this stimulus. I think it is necessary.”
Because the spinal cord plays an important role in the pain process, identifying which spinal neurons are directly involved in pain signaling may open the door to better pain management therapies.
“If we can identify the specific types of spinal cord neurons that play a key role in processing pain information, it may be possible to develop drugs that precisely target those cells,” Xie said. “Alternatively, we could use electrodes to stimulate neurons and modulate their activity so that pain signals are not sent to the brain.”
Scientists not only plan to optimize the design of the probe, but also plan to incorporate spinal NETs into a highly miniaturized, integrated data processing and stimulus feedback system.
In addition to developing the technology, Xie, Luan and their team have partnered with the Faff lab at the Salk Institute for Biology, the Weber lab at Carnegie Mellon University, and the Busbaum and Ganguly labs at the University of California, San Francisco. I am doing a series of studies. Conducting spinal cord research to test devices across different spinal regions, animal models, and research themes.
By developing and optimizing NET-based technology for spinal cord research, Ruan said he hopes to “provide the entire neuroscience community with the tools to achieve a more fundamental understanding of spinal cord function.” rice field.
“My real hope is that at the end of this project, four years from now, neuroscientists will be able to see and do new things that are not possible with current technology,” said Xie. rice field.
