The two former Max Planck researchers have been honoured for their discovery of light-sensitive ion channels
Peter Hegemann (left) and Georg Nagel.
© HU Berlin; Christian Wiese
To the point
- New research field: Peter Hegemann (formerly of the Max Planck Institute for Biochemistry) and Georg Nagel (formerly of the Max Planck Institute for Biophysics), together with Carl Deisseroth (Stanford University), are considered the founders of optogenetics. This research discipline uses light to study neural networks in the brain non-invasively. Light-sensitive ion channels, known as channelrhodopsins, act as switches that can control the flow of information within nerve cells.
- Possibilities for medicine: Optogenetics has not only revolutionised basic neuroscientific research but is also opening new possibilities for medicine.
Peter Hegemann led a research group at the Max Planck Institute for Biochemistry in Martinsried from 1986 to 1993. He received his first academic appointment at the University of Regensburg, before being appointed to the Humboldt University of Berlin in 2005. Georg Nagel was the head of a research group at the Max Planck Institute for Biophysics in Frankfurt from 1992 to 2004. He has been a professor at the University of Würzburg since 2004.
Channelrhodopsins are proteins found in the cell membrane of the single-celled green alga Chlamydomonas reinhardtii. They possess a light sensor, rhodopsin, which allows the alga to orient itself towards light to carry out photosynthesis. Because rhodopsin also functions as an ion channel, it is termed a channelrhodopsin. When stimulated by light, these membrane proteins become permeable to positively charged ions.
The gene sequence can also be transferred into animal cells, which is the basis for the term “optogenetics”. In this way, channelrhodopsins can be integrated into the membranes of nerve cells. The resulting influx of positive calcium ions then triggers an electrical signal. Other channel proteins become permeable to negatively charged ions when exposed to light, meaning that nerve cells can be activated or inhibited using light.
Therapeutic approaches in medicine
The discovery of light-sensitive channel proteins illustrates how basic research can lead to the development of new investigative methods and clinical treatments for humans. The use of channelrhodopsins and other light-activated channel proteins has therefore not only established a new field of research, optogenetics, but has also opened the door to new therapeutic approaches in medicine. For example, researchers at the University of Göttingen and the Max Planck Institute for Multidisciplinary Sciences are developing a new generation of hearing aids known as optogenetic cochlear implants. Visual aids for people with retinal damage are also currently under development.
