Optical modulation of ion channels

Optical modulation of ion channels is traditionally studied using a manual patch clamp system combined with a light source. This approach, however, is limited by a very low throughput. In the present work, we show data recorded using a 384-well based automated patch clamp system equipped with 384 integrated light sources (Qube Opto 384).

Optogenetics
In this study we evaluated Channelrhodopsin 2 (ChR2), a light-sensitive non-selective cation channel permeable to Na⁺, K⁺ and Ca²⁺ opened upon illumination (Berndt et al., 2012). Furthermore, we employed the chloride-conducting channelrhodopsin (iC++, Govorunova et al., 2015), which was developed from a non-selective cation conducting channelrhodopsin through a mutational approach.

Optopharmacology
Compound activation by light enables the pharmacological manipulation of receptors, ion channels and other proteins with a high degree of temporal control. We used caged GABA (Rubi-GABA, Zayat et al., 2003) to study the light activation of ligands, in combination with the microfluidic flow channel of the QChip 384, to give a higher degree of experimental control.