Optogenetics is a new age technology that attempts to counter the complexities of the nervous system using light; laying utmost emphasis on the scientific comprehension of how it works.

The average human brain is perhaps the most complex structure that we have observed or studied. Despite years and years of meticulous research, several parts of the brain still remain a daunting mystery. For several decades, due to our lack of adequate insights, brain diseases and abnormalities were treated by observing evident changes in the brain structure. Researchers and medical practitioners do not know enough to find the root cause of the problem while treating serious diseases like Alzheimer's and Parkinson's disease. Reason? They cannot probe into the function of the neurons deeply embedded in the folds of our complex yet fascinating brain. Hence, the medication and treatment are targeted to the entire brain. Optogenetics is a ray of hope that can find a cure for such diseases. The ‘brainchild’ of Ernst Bamberg, Ed Boyden, Karl Deisseroth, Peter Hegemann, Gero Miesenböck and Georg Nagel, optogenetics is a technology that controls living cells of the human body (neurons, especially) with the use of light. Their scientific breakthrough won them the ‘Brain Prize’ for the year 2013. This biological procedure is used in neuroscience by combining various approaches of optics and genetics in order to address the problem of ambiguity in the cure of diseases including but not limited to psychiatric disorders.

The brain contains about 100 billions of neurons wired to each other. Movement, actions, speech, reflexes etc. are a result of the sound functioning of specific neurons. The electrical signals carried by them are so rapid and accurately timed that keeping a tag on how the organ in its entirety conducts itself is a conundrum that medical researchers and doctors are solving through optogenetics. It makes use of fibre optic lights in order to have a more accurate look into the human brain. Fibre optical devices have been employed in telecommunications for several years. In fact, the lines responsible for your broadband internet connection are made of fibre optics. A much smaller and delicate version of it is used to get past the skull and explore the cells in the human brain. The practices of optogenetics were tested first on rats, mice, monkeys, worms and donkeys. The results observed were positive and reassuring. In the beginning of 2016, clinical optogenetic tests were conducted to cure chronic diseases and restoring complete vision to patients with retinitis pigmentosa.

How does it work?

The goal here is to understand the interplay of neurons that send electronic signals in the speed of milliseconds. Explaining optogenetics in the simplest way, it is the process of artificially modifying neurons in order to turn them off and on selectively by directing light of a specific wavelength on them. Light-sensitive proteins called ‘opsins’ are inserted into the cell membranes of a specific neuron(s), thus controlling it. Opsins are reagents that are genetically coded into the patient. With the help of light, the electrical activity of neurons can be excited or silenced; which is caused by cell hyperpolarization and depolarization respectively. Opsins alter their conformation when brought into contact with light.

In the human brain, there are several types of neurons that are responsible for specific conformations and disorders or pathologies. With the help of optogenetics, when a single neuron is silenced, scientists can discover what that particular neuron was responsible for. If it leads to a specific disease, it could be silenced, thus providing a cure for it. On activating a specific neuron, its capacities in performing a certain function can be realized. This breakthrough technology opens the world full of possibilities in treating any brain disorders. When the neuron responsible for a specific disorder is identified, the special area of the brain can be treated with the least possible side-effects of drugs. Optogenetics helps pinpoint the troublesome neurons accountable for abnormalities. These findings are merely the beginning of the awe that the concept of optogenetics encompasses within itself. 

Applications of Optogenetics:

Till date, optogenetics has been a popular subject of research amongst neuroscientists. It unravels the anomalies of the human brain whilst providing clinical solutions for neurological and psychiatry diseases as well as optical complications leading to blindness or unclear vision. Listed below are some vital applications of optogenetics:

• Understanding the neural network: On growing cultured nerve cells, the intertwined structure of neurons can be analyzed. The findings on how neurons contribute to behaviour can be used in introducing advanced technology and treatment of brain-related disorders.
• Gene Therapy: Although it is still a concept, through optogenetic tools, the application of gene therapy appears as a realistic possibility.
• Treating vision loss: Loss of photoreceptors results in vision loss. On delivering and activating the photosensitive opsins on the retina, vision can be restored.
• Treatment of brain diseases and spinal cord injury: Through the identification of the areas responsible for disorders, clinical treatment of several diseases incurable with existing technology can be provided.
• Pharmaceutical development: The study shows which parts of the brain are more susceptible targets for drugs. Drugs can be formulated accordingly for achieving maximum results.
• Future in non-neural systems: Optogenetics is not restricted to the nervous system. The presence of opsins in any cell membrane of living tissues such as muscle or cardiac cells can respond to the principles of optogenetics.
• Advancements in the clinical treatment of depression and anxiety: Changes in the neurons’ morphology in certain parts of the brain can be mapped to treat depression and anxiety.

Optogenetics comes with unprecedented challenges and risks which will be an interesting project to work on to discover therapeutic possibilities. The clinical and experimental assurance that o human brain.