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The 2026 Nobel Prize in Physiology or Medicine was jointly awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for discoveries that led to optogenetics — a technique that uses light to control specific nerve cells.
Context
Key Highlights
- What is Optogenetics?
- It is a technique that uses light-sensitive proteins to control the activity of specific neurons.
- Scientists can switch selected brain cells ON or OFF using light.
- Role of Channelrhodopsin
- Peter Hegemann and Georg Nagel discovered channelrhodopsin, a light-sensitive protein in the single-celled alga Chlamydomonas.
- When exposed to blue light, this protein opens a channel and allows ions to flow into the cell, producing an electrical signal.
- Contribution of Karl Deisseroth
- Deisseroth introduced the gene for channelrhodopsin into nerve cells.
- In 2005, he demonstrated that light could trigger nerve signals.
- In 2007, the technique was successfully used to control nerve cells in the living brain of mice.
- Why is it important?
- Earlier, scientists could mainly observe brain activity.
- Optogenetics allows them to actively control specific neurons and establish a cause-and-effect relationship between brain circuits and behaviour.
- It has helped researchers study memory, pain, emotions, thirst, hunger, reward, attention and social behaviour.
- Medical Applications
- It is being studied for neurological and psychiatric conditions such as Parkinson’s disease, Alzheimer’s disease, epilepsy, depression and schizophrenia.
- Researchers are also exploring it to restore vision in people with certain forms of blindness.
Example
- Think of the brain as a huge electrical circuit. Earlier, scientists could watch the circuit working, but could not easily control one particular wire.
- Optogenetics = putting a light-controlled switch on selected neurons.
- So, scientists can shine light on a particular group of neurons and observe what happens to memory, movement, emotion or behaviour.
Key Terms
- Optogenetics: Use of light to control genetically modified cells, especially neurons.
- Channelrhodopsin: A light-sensitive protein that acts as a switch for controlling cell activity.
- Light-gated ion channel: A protein channel that opens or closes when exposed to specific light.
- Neuron: A nerve cell that transmits electrical and chemical signals.
- Neural circuit: A network of interconnected neurons responsible for a particular function or behaviour.
- Causal relationship: Showing that one event directly produces a particular effect.
