Maps of the behavior of K_v voltage-gated ion channels are accessible online.

Ion channels located in cell membranes control the transport of various ions –– most notably sodium (Na) and potassium (K) –– into and out of cells. Voltage-gated ion channels on cell surfaces are involved in key cell functioning. In neurons and muscle cells, they are involved in neural transmission and muscle contraction. They operate by opening or closing in response to changes in voltage, allowing or preventing ions from moving.

Researchers have been studying voltage-gated potassium ion channels –– K_v channels –– for nearly three decades. Until recently, however, that raw data hasn’t been available for general use, and much of the processed data was manipulated in many different ways, leading to inconsistent and incompatible results. In addition, many K_v channels were not studied near body temperature.

The Blue Brain Project of the Ecole Polytechnique Federale de Lausanne (EPFL) has taken steps to address this issue. The group used a robot to automatically and rapidly record ion channels at body temperature, allowing them to overcome the high failure rate typically seen with manual studies.

The results (of over one million recordings from more than 9,000 cells) have been posted online in the form of a map of the behavior of all K_v channels, all of which have been examined under standardized conditions with large sample sizes. Channelpedia is a wiki-like platform from which the data can be downloaded.

The results show that, under similar conditions, K_v channels behave similarly across cell lines and species. Their behavior is significantly different, however, at different temperatures, with channels activating and inactivating more quickly at 35 °C than at 25 °C or 15 °C.

Some channels are inactive at lower temperatures but activate at higher temperatures. Others exhibit delayed activation not previously observed. There are also some channels that change behavior on a seemingly random basis that has yet to be explained but could account for previously reported inconsistencies.

Researchers around the world can access the data to develop improved models of K_v channels for use in drug discovery. The data and methods used to map the behavior of K_v channels can be applied to the screening of drug candidates. They can also be used to map other types of ion channels, something the Blue Brain Project is already pursuing. The group hopes to eventually establish a digital simulation of the brain.