January 17, 2019
A novel in vivo electrode design drastically reduces invasiveness, improving the fidelity of the eavesdropping.
Neuroscientists want to understand exactly what is going on in the brain as cells communicate to enable animals or people to perform complex actions, recall memories, be sentient, and interact with their environment. And they want to do this over time to investigate how the brain changes with age
NEW ELECTRODE DESIGN REDUCES INVASIVENESS OF IN VIVO ELECTROPHYSIOLOGY
One way to explore neuronal communication is to eavesdrop on neuronal conversations by using multielectrode arrays. The electrodes penetrate the area of interest and pick up neuronal electrical activity as voltage deflections, as the adjacent cell membranes are depolarized and repolarized, as passive and active potential changes whizz past them along neuronal processes.
historically, the draw back to this form of eavesdropping is that it is intrusive and invasive. Solid wire electrodes pushing through brain tissue can rupture blood vessels, or shear through brain tissue displacing or damaging cells. This damage not only impacts on the physiological behavior of the brain cells and therefore the animal, but can also impact on the sensitivity of the eavesdropping electrode to pick up on neuronal conversations. Inflammatory responses, like gliosis, can attack the probes and prevent a good contact between the neuronal membrane and the electrode. And, it is this level of contact that determines the signal to noise of the recording and therefore its fidelity. To pick up small changes in membrane voltage, you need excellent signal to noise.
The juxta-neuronal ultra-low impedance electrodes designed by Dr Romeo Racz at the Francis Crick Institute, London UK, achieve excellent signal to noise, cause negligible tissue damage and can be customized to the researcher’s needs.
Design Principles of jULIEs Probes
- Glass-ensheathed metal microwire based neural probes
- Nanostructure modified ultra-low impedance recording site
- Unit localization through signal intensity change with site displacement
- Extracellular recordings of up to 1.6mV at
optimaldistance from firing unit
- Un-detectable vascular disruption and tissue displacement
- Noble metal nanostructure platform compatible with bio-functionalization library
- Modular, flexible and scalable technology
- Compatible with Intan amplifiers