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The 2026 Nobel Prize in Physiology or Medicine was jointly awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for their work on light-gated ion channels and optogenetics. 

2026 Nobel Prize in Physiology or Medicine

The 2026 Medicine Nobel was awarded “for their discoveries concerning light-gated ion channels and optogenetics.”

  • Origin of the Discovery: The research began with the study of Chlamydomonas reinhardtii, a single-celled green alga that uses an orange eyespot to detect light and move towards it.

  • Light-Sensitive Channels: Peter Hegemann and Georg Nagel showed that channelrhodopsin functions as an ion channel that opens directly when exposed to blue light.

  • Controlling Neurons with Light: Karl Deisseroth introduced the channelrhodopsin gene into mammalian neurons and showed that blue-light pulses could trigger electrical activity in targeted nerve cells.

  • Animal Studies: In 2007, Deisseroth used fibre-optic light delivery to manipulate selected neural circuits in freely moving mice.

What Is Optogenetics and How Does It Work?

  • Genes + Light: Optogenetics combines genetic engineering with optical control. Scientists introduce microbial opsin genes into selected neurons, making them responsive to light.

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    • Opsins are light-sensitive proteins that bind to a vitamin A derivative called retinal to form the pigments responsible for vision and light perception. 

  • Targeted Gene Delivery: Researchers use engineered viral vectors to deliver opsin genes to specific brain regions or cell types without affecting neighbouring non-target cells.

  • Precise Neural Control: Specific wavelengths of light change the ion permeability of neuronal membranes, allowing researchers to activate or silence neurons with millisecond-level precision.

Why Is Optogenetics Important for Neuroscience?

  • Mapping Neural Networks: The adult human brain contains around 90 billion nerve cells. Optogenetics helps researchers identify how specific groups of neurons control information processing, emotions and memory.

  • High Precision: Unlike conventional microelectrodes and drugs that can affect surrounding cells, optogenetics can target specific genetically defined neurons and control them with millisecond-level precision.

  • From Observation to Intervention: The technique allows scientists to test whether particular neural circuits cause specific behaviours, rather than simply observing correlations between brain activity and behaviour.

  • Medical Potential: Researchers are studying optogenetics in conditions such as Parkinson's disease, depression, anxiety, schizophrenia and addiction. Clinical research has also explored optogenetic gene therapy for vision restoration and possible applications in cochlear implants.

Nobel Laureates and Their Contributions

  • Karl Deisseroth: A neuroscientist and psychiatrist at Stanford University and Howard Hughes Medical Institute who developed optogenetics as a method for controlling specific brain circuits in living animals.

  • Peter Hegemann: A biophysicist at Humboldt University of Berlin who identified light-induced currents in green algae, helping reveal light-gated ion channels.

  • Georg Nagel: A biophysicist at the University of Würzburg who established that ChR1 and ChR2 operate as ion channels directly activated by light

Source: INDIANEXPRESS

PRACTICE QUESTION

Q. Consider the following statements regarding the selection and conferral of the Nobel Prizes:

  1. All Nobel Prizes are selected and awarded by institutions situated exclusively in Stockholm, Sweden, to maintain absolute neutrality.

  2. The Nobel Memorial Prize in Economic Sciences was not a part of Alfred Nobel's original 1895 will but was established later by Sweden's central bank.

  3. A Nobel Prize can be shared by a maximum of three individuals, or it can be conferred upon organizations in all available categories.

Which of the statements given above is/are correct?

A) 1 and 2 only

B) 2 only

C) 2 and 3 only

D) 1, 2, and 3

Answer: B

Explanation:

Statement 1 is incorrect: Not all Nobel Prizes are awarded in Stockholm, Sweden. While the prizes for Physics, Chemistry, Medicine, Literature, and Economics are chosen and awarded by Swedish institutions, the Nobel Peace Prize is selected and awarded by the Norwegian Nobel Committee based in Oslo, Norway.

Statement 2 is correct: The Economics Prize was not part of Alfred Nobel’s original 1895 will. It was established much later, in 1968, by Sweden's central bank (Sveriges Riksbank) in memory of Alfred Nobel.

Statement 3 is incorrect: Although a Nobel Prize can be shared by a maximum of three individuals, it cannot be conferred upon organizations in all categories. Only the Nobel Peace Prize can be awarded to institutions or organizations (such as the Red Cross or the UNHCR). All other categories are strictly reserved for individual recipients.