For some are in the dark and others are in the light, and one sees those in the light, those in the dark one does not see.
These famous verses by Bertolt Brecht come to mind when you read the autobiographical information that the optogeneticist and biochemist Dieter Oesterhelt from Munich, who died in 2022, gave about his "life with light and color". Oesterhelt is a shining light in the history of science, but hardly anyone in the public knows his name. The major topic of his research at the Max Planck Institute of Biochemistry in Martinsried was the question of how bacteria capture light, and it was known that macromolecules called rhodopsin are responsible for this in the human eye. Oesterhelt was able to show that not only highly developed organisms, but also some low-ranking bacteria have such pigments, which were then called bacteriorhodopsins and allowed their mode of action to be studied in a special cell envelope called the purple membrane. They functioned as light-driven pumps for protons. Oesterhelt interpreted the cellular work of his pump to mean that bacteriorhodopsin allowed a type of photosynthesis otherwise known from plants. "I struggled for years to get this into the textbooks. It took thirty to forty years. It's incredible how slow scientific progress and knowledge can sometimes be in surprising cases." So much for the standard thesis that everything always happens faster in research, which, according to Oesterhelt, is often prevented because he has identified "a bad trend in science". "Everyone is running after the same thing. The daring to do something new, even in the face of resistance, that's the real science - to claim that something can and must work, to pursue this goal and to be ridiculed for it." In his autobiographical notes, Oesterhelt emphasizes his role as a basic researcher who wanted to give others the chance to try out applications, and optogenetics has since become a technology with which cellular activity can be regulated through the use of light. Foreign genes are introduced into target cells, where they then synthesize the required molecules, which can now partially restore sight to blind patients.
