Optogenetics

How exactly does optogenetics work?

It is arguably the most revolutionary technique in modern neuroscience.

Optogenetics allows researchers to turn specific individual neurons on or off using literal flashes of light.

Light.

Like a laser.

It explores happily.

It has no memory of the threat.

Optogenetics provided the absolute definitive causal evidence that these specific neuronal ensembles are the physical substrate of memories.

This year's award went to Karl Deisseroth at Stanford University, Peter Hegemann at Humboldt University of Berlin, and Georg Nagel at the University of Würzburg in Germany.

They were recognized for their discoveries around light-gated ion channels and optogenetics.

Optogenetics allows scientists to switch individual brain cells on and off.

Because neurons use electrical signals to communicate with one another, scientists realized almost a century ago that they could use electrical stimulation to activate brain cells.

Optogenetics combines this idea with genetic engineering to allow for more targeted, less invasive, safer cell stimulation than used to be possible.

After genetically modifying neurons to make proteins that react to light, researchers can control those cells with a flash of light instead of an electrode.

Hegemann and Nagel contributed to the field by studying a single-celled alga that swims toward light, which they found had to do with a particular protein that opened up pores in the cell membrane when exposed to light.

Karl Deisseroth is Professor of Bioengineering and Psychiatry and Behavioral Studies at Stanford University.

Together with German scientists Peter Hegemann and Georg Nagel, he received the Nobel Prize for Optogenetics, a method for controlling nerve signals with light that the Nobel Assembly said has laid the foundation of a new era of neuroscience.

Dr Karl Dyseroth, congratulations and welcome to Sunday Extra.

Thank you very much.

And we're now playing in different patterns of activity into a kind of cell called the dopamine neuron, and we're determining that some patterns of activity, but not others, turn out to control feelings of reward or motivation, and that may help us understand these psychiatric diseases.

Researchers since have been able to use optogenetics to reveal how neural circuits lay down memories and behaviors, and clinicians are now even exploring the method as a way to restore sight in people with visual impairment and as an alternative to drugs to dial down electrical activity and stop epileptic seizures.

The Nobel Assembly praised the work for laying the foundations of a new era in neuroscience, saying, "Optogenetics has fundamentally altered our understanding of the brain.

Every day brings new discoveries, helping to solve one of humanity's greatest mysteries, how our incredible brain works." For Deisseroth, the recognition was both personal and professional.

He described receiving the prize as absolutely wonderful and said it was an honor to share the accolade with his friends.

Um, but the next one i-i-is for a tool as well.

Let's hear what optogenetics is from Gyorgy Nagy.

Optogenetics is the manipulation of a cell or a complete animal by illuminating it with the correct wavelengths.

So for example, in our case, it was the blue light.

In red light it would not respond, but with blue light it responds, and you can do this only via genetically modifying this cell or animal or plants.

This is Litwiz30, literary wisdom in under thirty minutes.

And today's episode is From Algae to Nobel: How Optogenetics Lit Up the Brain and Restored Sight.

We'll walk through five stops on the journey from a pond-dwelling alga to a Nobel Prize-winning tool and now a sight-restoring gene therapy.

First stop: the algal origin.

Another landmark study in 2012, led by Susumu Tonegawa, reactivated fear memory engrams, showing that stimulating a precise set of neurons could cause mice to freeze as if recalling a shock.

These experiments illustrated a broader truth.

Optogenetics could map the causal role of virtually any circuit, from pain pathways to social behavior, thirst, feeding, reward, attention, circadian rhythms, and even fever responses.

To put the scale in perspective, the adult human brain contains roughly 90 billion neurons, each forming thousands of synapses.