Alexander Gottschalk studies the mechanisms and subcellular structures mediating synaptic transmission, as well as the neuronal control of behavior in the nematode Caenorhabditis elegans. In 2005, he demonstrated that neuronal expression of the light-gated channel Channelrhodopsin-2 allows controlling neuronal activity and, downstream, the movement of an intact animal with light, making him one of the pioneers of Optogenetics.