Ultra-Flexible Neural Probes Open New Doors for In Vivo Brain Research

Researchers at Stanford University and Harvard Medical School have developed tiny and ultra-flexible mesh neural probes that can be implanted into sub-100-micrometer-scale blood vessels in the brains of rodents.

Micro-endovascular (MEV) probe selectively implanted into a curved branch for neural recording across the blood vessel wall. The MEV probe (yellow), which is designed to curve into branched (vs. straight) blood vessels, is selectively injected into the branched vessel by saline flow through the microcatheter (cyan) in which it was preloaded. Credit: Anqi Zhang, Stanford University

The probes are delivered into the brain through a minimally invasive procedure that does not require open-skull surgery. This makes them a promising new tool for in vivo brain research, as they can be used to record neural activity in deep brain regions that are difficult to access with other methods.

The probes are also very flexible, which means that they can be implanted into tortuous blood vessels without damaging the brain or the vasculature. This makes them a potential option for long-term brain recording, as they are less likely to cause scarring or inflammation than traditional neural probes.

The researchers have demonstrated the potential of their probes by recording field potentials and single-unit spikes in the cortex and olfactory bulb of a rat. They have also shown that the probes can be used to selectively implant in different brain branches by tuning the mechanical properties of the probe.

The development of these ultra-flexible neural probes is a significant advance in the field of in vivo brain research. They offer a new way to record neural activity in deep brain regions without the need for invasive surgery. This could lead to new insights into the function of the brain and new treatments for neurological disorders.

 Anqi Zhang et al, Ultraflexible endovascular probes for brain recording through micrometer-scale vasculature, Science (2023). DOI: 10.1126/science.adh3916
Brian P. Timko, Neural implants without brain surgery, Science (2023). DOI: 10.1126/science.adi9330