An electronically controlled neural probe can now electrically and chemically record and stimulate single neurons in the brain. Such is the creation of IMEC, along with its partners within the European FP6 Program, NeuroProbes. Potential applications are numerous, ranging from tools for fundamental research on the functioning of the brain, to instruments for more precise diagnosis of brain seizures before brain surgery.
To discriminate single neurons in the brain, the recording electrode must be positioned very close to the neuron, ideally within 100 micrometers or less. To date, multi-electrode recording probes have relied on trial and error, since it’s not possible to mechanically optimise the position of electrodes independently from each other.
Thanks to the new Electronic Depth Control (EDC) technology, the different electrodes can be individually adjusted without requiring any mechanical displacement. The EDC neural probe features hundreds of electronically switchable electrodes, allowing it to scan for important neural signals. Then it can lock onto the signals and eventually adjust their position during the course of an experiment.
The EDC neural probe technology also opens the door to dozens of new research tracks, and even promises to refine work currently underway. Next to fundamental brain research, one of the key roles of the EDC technology is pre-operative diagnostics prior to brain surgery for a variety of conditions.
In-Vitro Study Of Brain Tissue
In addition to the creation of the neural probe technology, IMEC, in conjunction with Piera, a manufacturer of pharmaceutical and chemical research instruments, developed an innovative slice-tilting instrument for in-vitro research on brain tissue. The new tool enables long-term study of brain cultures through electronic stimulation and read-out, essential in getting insight into the functioning of the brain.
To increase knowledge on neuronal networks and on the cellular processes causing neurodegenerative diseases, such as Alzheimer’s disease, brain-tissue slices need to be observed for longer periods of time. Keeping brain tissue slices alive to study long-term effects in neuronal circuits requires that the slices be cultured. In other words, they must attach to a substrate and start growing. Such a brain procedure is believed to be one of the most challenging cultures in the medical world.
IMEC and Peira developed a custom slice-tilting device that contains up to 16 chips with stimulation and read-out electronics, specially customised to grow brain-slice tissue. The tilting device is incorporated in a cell growth incubator. Parameters such as tilting angle, speed, and interval time can be programmed to obtain optimal growth, survival, and functionality of the brain slice.
The new tool ensures optimal growth of brain slices on the chips for more than a month. As a result, researchers can now perform in-vitro investigation of long-term processes in brain circuits.