Login with Facebook

What is optogenetics?

Optogenetics was developed in the early 2000s; it is the combined use of genetic and optical (light) methods to control genes and neurons. It is among the most rapidly advanced technologies in neuroscience and has the potential to revolutionize the way scientists study the brain. 

What is optogenetics

Optogenetics is an experimental method in biological research that involves the combination of optics and genetics in technologies that are designed to control (through excitation or inhibition) well-defined events in the cells of living animal tissue. Unlike experimental methods previously developed for light control, optogenetics allows researchers to use light to turn cells on or off with remarkable precision and resolution (down to individual cells or even regions of cells) in living animals and in movement. As a result, it can be used not only to control specific behaviors in animals, such as triggering or blocking fear or pain but also to thereby deduce the contributions of individual cells to those behaviors.

Since the 1970s, many laboratories have identified various trans-membrane proteins called opsins, which react to light by opening and allowing the selective passage of charged ions through them. In the late 90s, the first research was carried out in some laboratories to exploit these proteins in the control of neurons, in a very elegant way to provide those who want to study. Despite the fact that it was conceptually simple, it is only in 2005 that the team of K. Deisseroth, MIT. They managed to publish a revolutionary article, integrating one of these opsins, called Channelrhododopsina-2 (ChR2), to those normally present in a culture of murine brain cells. The researchers were able to activate the neurons with a temporal precision of the order of milliseconds by turning on a laser. Now optogenetics has become a relatively widespread and applied technique on numerous species, from worms to non-human primates.

Its use can serve to confirm hypotheses or knowledge previously acquired in another way, to clarify the functioning of some phenomena, to distinguish the influence of the various neurons on the behavior of the guinea pig live, or to manipulate the mind.

It is a technique that "will allow many brain diseases to be treated effectively in the near future,” so researchers promise.

With precise time pulses of light aimed at targeted tissue regions or cells, optogenetics allows the researchers to activate or block events in specific cells of living animals. A mouse with a paw made hypersensitive to touch. For example, the pain response can be eliminated by making the yellow light shine on the affected paw, the cells in which they were aimed at expressing a type of light-sensitive microbial protein known as opsin.

Optogenetics on humans

The first human trial involving optogenetics began in 2016 and was designed to explore the potential use of technology for the treatment of patients with hereditary retinitis pigmentosa. The progressive degeneration of the retina, the hallmark of the disease, causes serious vision problems. At least 15 patients who were blind or mostly blind were expected to participate in the study, and each of them would receive an injection of virus that carried genes encoding the opsin targeted specifically to retinal ganglion cells (RGC). 

One of the main objectives of the test was to establish sensitivity to light in RGCs, which are usually not affected by retinitis pigmentosa and normally transmit visual information from the photoreceptors in the eye to the brain. In the presence of blue light, the RGCs expressing the opsin would start sending visual signals to the brain.

Optogenetics seems to open immense horizons to researchers, who can already modulate nerve activity through the stimulation with optic fibers of photosensitive proteins called opsins produced ad hoc inside neurons; but with light.

It is also possible to control the switching on or off of the genes, in a refined form of epigenetics. This way, we could define it as artificial that will give us the opportunity to activate the beneficial genes and deactivate the dangerous genes at our convenience.

Although the extent to which optogenetic treatment improved vision was uncertain, the results of the study were highly anticipated. Other optogenetic therapies are being developed for a wide range of diseases, including chronic pain and Parkinson's disease.

Optogenetics: Controlling the brain with light

Our brain is undoubtedly the most complex machine. It must be said that in humans, there are not far from 100 billion neurons linked together by nearly a million connections. No wonder it is hard to understand how this damn brain works.

And yet over the past ten years, a new technique has appeared which is perhaps poised to revolutionize neuroscience i.e., optogenetics.

The brain, a delicate organ to study

A brain is a large bundle of neurons linked together, and which spend their time activating and deactivating. When a neuron is activated, it sends an electrical signal to the other neurons to which it is connected; it is said that the neuron discharges.

By simplifying, we can see the brain as a huge machine with billions of switches that would spend their time alternating between "on" and "off." 

And what do you normally do to try to understand how a machine full of buttons works? Perhaps we press the buttons one after the other and watch what is happening. The problem is that we can't do that with the brain. It is indeed almost impossible to stimulate only one given neuron while leaving the others unchanged. We are generally reduced to observing the working brain and trying to deduce something about the role of neurons or given brain areas.

How to stimulate neurons?

Of course, in certain cases, it is possible to activate a region of the brain that interests us by inserting an electrode delivering electrical impulses (as opposite on a mouse). However, this method has the defect of generally exciting an entire area, without making it possible to target a given type of neuron.

An alternative is to inject molecules capable of binding to certain categories of neurons to stimulate or inhibit them. This can allow better targeting, but in this case, we lose all reactivity because the effects are manifested on time scales of several hours. Not ideal when you know that in the brain, signals act in a few milliseconds. The dream would be to have a technique allowing both to target certain neurons selectively while allowing stimulations over very short periods of time. Well, that's what allows optogenetics to do. But to understand how this technique works, we must first review the way communications work in our brain.

The brain, a giant electrical circuit

In the most classic configuration, one neuron in the brain can be connected to another by means of an extension called an axon, which allows the propagation of electrical signals. It is quite tempting to see the axon as conducting wire carrying electricity, but we will see that this analogy is a little incorrect.

Almost everywhere in our body, there are ions, that is to say, charged atoms, some positively like Na + or K +, others negatively like Cl-. However, the distribution of these ions is not the same on each side of the membrane, which delimits the neurons; the charge is thus slightly lower inside. 

This results in a small potential difference of around -70mV on either side of the membrane of our neurons. It is said to be polarized. However, neurons are able to modify this polarization, and the ingredient that allows them to do so is a protein inserted into their membrane, the sodium channel.

The sodium channel, in fact, behaves like a door capable of allowing Na + ions to pass or not from the outside to the inside. When this happens, the charge inside increases and the potential can go from -70 to + 100mV, a threshold beyond which the sodium channel closes, and the polarization drops to -70mV. This momentary change in polarization takes only a few milliseconds and is called an action potential. Initially, it will generally be created in the main part of the neuron. We must now understand why this potential can propagate along the axon.

What allows this propagation is a peculiarity of these channels letting the sodium ions pass, they tend to open precisely if their vicinity becomes depolarized. So if a channel opens, a depolarization takes place, stimulating the opening of the neighboring channel, and so on by domino effect all along the axon. And it is through this kind of chain reaction that a signal can propagate along the axon of a neuron to the neurons to which it is connected. This is how the neuron discharges.

Channelrhodopsin: the key ingredient in optogenetics

Now that we have seen how electrical communications propagate in cells, we can present the star of the show, the key ingredient in optogenetics, channelrhodopsin 2 (ChR2). ChR2 is a protein discovered in 2002 in a unicellular alga with the sweet name of Chlamydomonas reinhardtii. It is very similar to the sodium channel since it inserts into the cell membrane and can pass ions. But its big peculiarity is that its opening is controlled by light. In fact, when you throw blue light at it, the protein ChR2 changes shape and gives rise to a small hole of around 6 Angstroms, enough to let the ions pass inside the membrane.

It was while reading a publication on ChR2 that the biologist Karl Deisseroth and his team came up with the idea that underlies optogenetics. If ChR2 behaves like a channel responding to light, it can be used to unload neurons on demand.

The founding experiment then took place in 2005 at Stanford University in the United States. Deisseroth and his team cultivated neurons in which they implanted the protein ChR2 in a Petri dish. And they then observed that the latter started to discharge when they were lit with blue light. Here is the technique that everyone was waiting for! It is a way to activate neurons in a given region by simply sending them lightly. It remained to implement the technique with a real brain.

Control the brain with light

When the blue light is on, the mouse starts to spin frantically counterclockwise. And it stops when the light signal is turned off. It's a little scary and even cruel. But you can imagine that the purpose of the technique is not to have fun and laugh on the back of our rodent friends. Optogenetics makes it possible to stimulate in a rapid and targeted manner specific areas and neurons of the brain and to understand the impact of their activation on the behavior of the animal. So it's a great way to unravel the web of neural connection to our favorite organ and to better understand how it is wired.

At this point, you may be wondering what the advantage of the method is over conventional electrical stimulation, where electrodes are inserted into the brain to balance electrical impulses. 

Well, the main difference is that with optogenetics, we can target specific types of neurons because all neurons are not identical. Take, for example, the dopaminergic neurons, those that use this hormone called dopamine. These neurons are comparatively very few (on the order of only 400,000 in the human brain), and yet they play an essential role to the point that their dysfunction is considered to be one of the causes of Parkinson's disease. One of the treatments for Parkison's disease consists precisely in performing stimulations using electrodes implanted in the deep areas of the brain. 

Control the expression of ChR2

For the moment, we have passed over in silence the way in which it is done so that the protein ChR2 is found inserted in the membrane of neurons. Naturally, this protein is produced in a very specific unicellular alga, but not at all in the brains of animals. In order for this to work, we must, therefore, ensure that the neurons that we target begin to produce this protein. As you may know, in the living world, proteins are produced from DNA. Part of the genes serves as a blueprint for making proteins. So for a cell to start producing the ChR2 proteinoptogenetics, we must provide it with the corresponding DNA that we have previously extracted from our unicellular alga.

Author: Vicki Lezama

Need a custom

We will write it for you.
Order now

Free Essay Examples

Free essays:

All you need to know about Neuroendocrinology
All you need to know about Big data management
All you need to know about digital special effects
All you need to know Technical Writing?
Basics the Game Theory in Cryptoeconomics
Business innovation ideas for making money
Biosensors for cancer diagnosis
Business Analysis: Pricing strategies and Demand Curve
Cognitive Computing- How does Cognitive Computing work?
Consciousness: characteristics and peculiarities
Conservation Economics
Cybersecurity in business: challenges, risks, and practices
Demographic trends and how they affect Economic Growth
Dance as an art form and entertainment
Discrimination Economics
Determinants of Wages
Everything you need to know about short-term memory
Economic and Policy Impacts of Demographics
Ethics: an essay on the understanding of evil
Emotions: what are they? Theories explained
Factors of Demographic Data Collection
Factors Affecting Purchasing Behavior
Financial Statement Analysis
Factors Influencing Interest and Exchange Rates
Government's Intervention in The Labor Market
Guide on the Pathways of the nervous system
Game theory in microeconomics
Globalization: definition, causes, social impact and risks
How Relativism Promotes Pluralism and Tolerance
How to use the audience’s feedback to write a news report
History of silent cinema
How news report can be strengthened through multimedia
Introduction to Population Problems
Imperfect Information and Asymmetric Information
Imperfect Information in Insurance
Introduction to Labor Markets
Journalism: What is News?
Journalism: Broadcast media and Television Presenters
Journalism: Sources of News
Journalism and Law
Key Determinants of National Income
Key Factors That Affect Pricing Decisions
Kinetic models in biology and Related fields
Know about the different forms of traditional African dances
Latest technology trends
Latest dance trends
Magnetoencephalography (MEG)
Microeconomic Analysis to the Demand for Labor
Neuromuscular disorders
National Economies, Fluctuation, and Responses to Fluctuations
Neurotransmitters: what they are and different types
Nanomedicines to target tumors
Objections to utilitarianism
Organizational motivation and its effects
Overcoming Hiring Challenges for Nonprofit Organization
Population Demographics
Recurrent neural networks (RNN) for speech detection
Russian School of Mathematics
Research and Development
Risk Sharing in Insurance and Asset Markets
Stochastic optimization methods in deep learning?
Structure of the nervous system
Structure of a Corporation
Schizoaffective disorder: how to live better with it
The climate change denial
The techniques of basic cinematography
The Endosymbiotic Theory
The Role of Internal Audit in Corporate Risk Management
Utilitarianism Vs. Kantianism
Understanding Auctions and Auction Theory: Part 2
Various theoretical perspectives of sociology
Virtual reality, what it is and how it works
What are the linear models in machine learning?
What is Convolutional Neural Network
4 Facts about Origin of Mathematics!
5 techniques to create an animation
10 emerging technologies according to World Economic Forum
10 strategies to maximize corporate profits
3d Model Of Building
6 Medical Technologies that revolutionized the healthcare in 2020
All you need to know about the ACA Code of ethics
Architecture and Democracy: An Introduction
Architecture and Democracy: Democratic Values
Architecture and Democracy: Democratic Procedures
All You Need to Know About a Synthesis Essay
An essential guide to understanding Film Theory
Application of Artificial Intelligence in Cyber Security
Applications of electrical engineering
Augmented reality: what it is, how it works, examples
Advantages And Disadvantages Of Social Networking
All you need to know about Cryptography
Applications of astrophysical science
All you need to know about architecture engineering
Applications of geological engineering
Artificial intelligence and medicine: an increasingly close relationship
An insight into Computational Biology
ACA code of conduct
A Rose for Emily
Applications of Mathematics in daily life
Architecture mistakes to avoid
All you need to know about Toxicology
All you need to know about Holistic Medicine
All you need to know about linguistics
An introduction to Linguistics and its subfields
All you need to know about Anxiety disorder
All you need to know about Drones
A Brief Insight into Political Science
Assumptions related to feminism
All you need to know about Byzantine emperors
All you need to know about labour economics
An insight into xenobots -the first-ever robots
An ultimate guide about Biomaterials
A Comprehensive Introduction to the Mona Lisa
Analysis methods of Transport through biological membranes
An ultimate guide about biochemical reactions
Analysis of brain signals
Artificial Gene Synthesis
Application to synthetic biology of CAD methods
All you need to know about metabolic pathways
Applications of BIOMEMS
All you need to know about the epidemiology
Asian vs. western leadership styles
All you need to know about Smart prosthesis
Analysis of Economy: Output of Goods and Services (GNP), and GDP on Economic success
A Guide to Pricing Strategies
An Overview Of Economic Studies
Analysis of Fiscal and Monetary Policies
Analysis of Business Cycles
Analysis of Consumption and Investment
A Look into Regression Analysis
Analysis of Household's Consumption and Savings Behavior
All you need to know about Capital Budgeting
All you need to know about risk management
Art looted in wartime.
Appropriate use of Data in Economics
All you need to know about reaction kinetics?
A historical overview of Financial Crises
All you need to know about management discipline?
An insight into the error-correction models
All you need to know about Data visualization
All you need to know about Work-family balance
All you need to know Technical Writing?
All you need to know about digital special effects
All you need to know about Big data management
All you need to know about Neuroendocrinology
How to Write a Personal Essay
Housing Needs in America
How to Write a Description Essay
How to Create an Excellent Scholarship Essay?
How to write a cause and effect essay
How to Hire the Best Essay Writing Service Provider?
How to Write a College Application Essay?
How to get the most out of your English lectures
How to write Expository Essay
How to succeed in your psychology class?
How to Write an Academic Essay in the Shortest Time?
History of Journalism
How Different Sectors are Using Artificial intelligence (AI)
How to write an informative essay
How to deliver persuasive essays?
How to Give a Convincing Presentation
How to write an essay on leadership?
Historical Art Still Around Today
Humanoid robot: what it is, how it works and price
History of Chemistry
Healthcare Advanced Computer Power: Robotics, Medical Imaging, and More
Healthcare AI: Game Changers for Medical Decision-Making and Remote Patient Monitoring
How to understand different types of English
How to Cope with Chronic Pain
How African American choreographers and dancers have influenced American dance
How mobile robot can do in logistics or in production
How To Become a Successful Entrepreneur
History of the Philosophy of Feminism
How is the climate changing?
How to Track Your Content Marketing ROI
How to Gun control In the USA?
Historical and contemporary role of labour in the modern world
How breast cancers are classified?
How the cells of our body communicate?
How the Lymphatic System Works?
How Digestive System Works
How to complete your capstone projects effectively?
How to write a research project
Healthcare technologies that help patients with better self-management
How to choose the topic of the senior capstone project
How to make your business survive at economic crisis
How can immigrants blend in the American society?
How does the economics of war affect society?
Hate speech on social media.
How to Build an Economic Model
How to start a healthcare startup?
How can financial illiteracy harm you?
How cancer is developed - Cancer biology
How to define the Enterprise Value
How to conduct economic research?
How women can manage sexual harassment
How to use quotes in your news reports?
How news report can be strengthened through multimedia
History of silent cinema
How to use the audience’s feedback to write a news report
How Relativism Promotes Pluralism and Tolerance
Introduction to Urban Studies
Importance of dance in education
InMoov: how to build an open source humanoid robot
Importance of KYC verification to making the Blockchain secure
Importance of Rhythm
Importance of dance student evaluation
I/O control methods -types and explanations
Identity theft: what to do?
Introduction to Utilitarianism
Importance of 3d Modelling in Architecture
Importance of online journalism
Image processing in medical diagnosis
Introduction to USA Politics
Introduction to Comparative Politics
International Relations as a Major in Political Science
Importance of modern trade policy
Introduction to Journalism
Introduction to Writing a TV Script
Introduction of Microfabrication techniques
Introduction to Microeconomics
Interaction of Consumer and Firm Choices in Markets
Importance of corporate sustainability
Issues in International Monetary Macroeconomics
Introduction to Statistics and Data for Economics
Introduction to Data and Probability for Economics
Introduction to the Game Theory
Introduction to Econometrics
Introduction to Economic Information
Introduction to Market Equilibrium
Introduction to Economic Models and Application
Introduction to Empirical Research
Introduction to Econometric Data
Importance of Critical Thinking, Principles, and Goals
Introduction to Identification and Causal inferences
Introduction to Econometric Application
Intermediaries and Government in Financial Crisis
Importance and seven principles of quality management
Illiteracy in the USA
Introduction to Economics of Law
Introduction to Coase Theorem
Introduction to Social Choice and Incarceration
Intellectual Property and Product Liability
Investment in Human Capital
Introduction to Labor Markets
Imperfect Information in Insurance
Imperfect Information and Asymmetric Information
Introduction to Population Problems
The Looming Energy Crisis in America
Top benefits of performance-based engineering
The More Languages You Know, The More Times You Are a Man
Things to consider while writing an Argumentative Essay
Top Ways to Improve Your Academic Writing Skills
Tips to Excel in Creative Writing
The origins of films in the early 19th century
Top career options in Architecture
The Elevator Pitch
Top finance trends 2020
The basic Structure and functionality of robots
The Way to Success
The election system of the President in the United States of America
Two-party System in United States of America
Top trends in urban design
The history and theory of African American filmmaking
Top benefits of creative writing
Tinnitus Guide: Common Symptoms and Treatment Options
The language of dance
The digital image processing management
Top famous politicians of the World
Top methods of political science!
The history of the feminist movement
The blood flow in cardiovascular system - Biofluid Mechanics
The best of Leonardo Da Vinci
The Structure and Function of Macromolecules
The structure of cell: a research on the bricks of the human body!
Tissue and organ construction: Adhesion and recognition between cells
The kinetics of the transformation processes
The Modeling of Biological Systems
Tips for writing a great thesis statement
The Defense mechanisms against infections
The impact of the technological innovations in medicine
Top journalism trends to know about
The relation between mass media & politics
Theranostics: Diagnosis and Care through Nanoparticles
The practical Applications of X-rays
The applications of Ultrasound in medicine
Transfer mechanisms of genetic information in Bacteria
The regulation of cellular metabolism in the diagnosis
The Principles of MRI Contrast agents
The technical basis of optical coherence imaging
The New Media: Emerging Trends
The Structure of Interest Rates and the Yield Curve
Technological perspectives and reflections of neural engineering
Types of bioreactors and their applications
The Role of Government Policy in Improving Economic Outcomes
Types of corporate responsibility
The Role of IMF in International Monetary Macroeconomics
Tools for investment decision making
The concept of Organizational Culture and its applications
The Conduct of Monetary and Fiscal Policy
The Basics of Financial Accelerator Models
Tips for labeling medical devices- Medical Entrepreneurship
The different medical imaging techniques
The Economics of Uncertainty – Introduction
Theories of Public Policy
The Game Theory in Social Media
The political theory of Thomas Hobbes
The Use of Law on Economics and Vice Versa
The Role of Internal Audit in Corporate Risk Management
The Endosymbiotic Theory
The techniques of basic cinematography
The climate change denial
What is a Definition Essay?
What are diagnostic essays?
What is the relation between art structural engineering?
What is a Narrative Essay
What are robotics and intelligence systems?
What are the benefits of studying health sciences?
What is artificial intelligence and why it matters?
What is comparative Literature?
Why study neuroscience
What is Wi-Fi and how does it works
What is French history famous for?
What are Humanistic Studies?
What is covered in Biophysics?
What is modern journalism?
What is Virtualization? Benefits & Applications
What are modern public relations?
What is plasma physics?
What is teacher preparation?
What is rapid prototyping for 3D printing?
What is contemporary European Politics?
Why should you learn American Ballet?
What is engineering physics?
What is the purpose of African American Literature?
Ways to learn the Rhythm
What is digital art used for?
What are Enzymes and how do they work
Who is the father of political science?
Why Study Political Science - Job?
What is the Philosophy of Feminism?
What is a quantum computer?
Ways B2B Startups Streamline Their Conversion Strategies
Why do biomedical signals need processing?
What are the long term effects of climate change?
Why study labour relations
What is Holoprosencephaly?
What is antisocial disorder?
What are the important principles of evolution?
What is the cytoplasm and its function?
What is biopolymers?
What Makes a Good Leader
Women empowerment in modern generation
What is the history of political thought?
What is Gene recombination
What is synthetic biology
What is business cost analysis?
What is Inflation
What are the consequences of unemployment?
What is lithotripsy and its types?
What is transition elastography?
What is the purpose of deep brain stimulation?
What is a Brain-Computer Interface (BCI)
What is neuroethics?
What is Market and Supply and Demand
What is optogenetics?
What are the techniques to record brain activity?
What happens if the interest rate increases?
What is immunotherapy?
What is the economic role of the financial market?
What are the factors behind illegal immigration?
What is the lymphocyte activation?
What is financial market and its types?
What is the structure of financial markets?
What are the methods of measuring business performance?
What is the Credit market?
What is business ethics and code of ethics
What are the Causes of financial instability?
What is MBA with Concentrations
What is regenerative medicine?
What is Population ecology?
What is Microfinance: evolution, and practices?
What is biotechnology and its applications?
What are Workplace diversity and its benefits?
What is the difference between a leader and a manager?
What Is Branding and best branding Business strategies?
Why are microelectronics important?
What are biologic drugs.
What is the Foreign Exchange market?
What is the role of scientific research in times of crisis?
What are the risks of international trade?
What is financial management?
What is gene therapy?
What is education economics?
What is regression analysis, and why should you use it?
What Is Technology Marketing And How Should It Work?
What is Management Accounting
What are the methods of valuation of companies?
What is Immune System and Immunotherapy?
What is big data analytics?
What is the 7 layers of OSI model?
What is Neuroplasticity?
What are Sculpture art and its types?
What are the different genres of films?
What is Transcranial magnetic stimulation (TMS)?
What is TES-Transcranial electrical stimulation?
What is Relativism?
What is Vaccine skepticism, and what to do about it?
What happens in the brain when learning?
What is the deep neural network?
What is Convolutional Neural Network
What are the linear models in machine learning?