Recording thousands of nerve cell impulses at high resolution

For above fifteen years, ETH Professor Andreas Hierlemann and his group have been creating microelectrode-​array chips that can be applied to specifically excite nerve cells in cell cultures and to measure electrical cell action. These developments make it feasible to increase nerve cells in cell-​culture dishes and use chips located at the bottom of the dish to look at each person cell in linked nerve tissue in depth. Alternative techniques for conducting these kinds of measurements have some apparent restrictions. They are either extremely time-​consuming – since call to each cell has to be independently set up – or they need the use of fluorescent dyes, which impact the behaviour of the cells and hence the consequence of the experiments.

Close-​up of the new twin-​mode chip. The measurement place in the centre of the image (eco-friendly) is 2 x four millimetres. Graphic credit rating: ETH Zurich / Xinyue Yuan

Now, scientists from Hierlemann’s group at the Department of Biosystems Science and Engineering of ETH Zurich in Basel, with each other with Urs Frey and his colleagues from the ETH spin-​off MaxWell Biosystems, formulated a new technology of microelectrode-​array chips. These chips help detailed recordings of significantly a lot more electrodes than preceding units, which opens up new programs.

Much better sign demanded

As with preceding chip generations, the new chips have all around twenty,000 microelectrodes in an place measuring 2 by four millimetres. To make sure that these electrodes decide up the rather weak nerve impulses, the signals need to have to be amplified. Examples of weak signals that the scientists want to detect incorporate these of nerve cells, derived from human pluripotent stem cells (iPS cells). These are presently applied in quite a few cell-​culture illness products. Another purpose to significantly amplify the signals is if the scientists want to observe nerve impulses in axons (good, extremely thin fibrous extensions of a nerve cell).

Nonetheless, superior-​performance amplification electronics acquire up room, which is why the preceding chip was able to concurrently amplify and study out signals from only one,000 of the twenty,000 electrodes. While the one,000 electrodes could be arbitrarily selected, they experienced to be identified prior to each individual measurement. This intended that it was feasible to make detailed recordings above only a fraction of the chip place during a measurement.

Measuring chip at the foundation of a cell-​culture dish. Graphic credit rating: ETH Zurich / Xinyue Yuan