Optogenetics

Written by Ayebamiebi Yousuo

Introduction 

"Cells that fire together, wire together.”_Daniel O. Hebb 

So how do we know and study the cells that fire together without stimulating surrounding cells? That's one question that optogenetics is answering. 

With this technology, neuroscientists have been able to study different groups of neurons by either turning them off or on without stimulating their surrounding neurons. With this technology, they have been able to study cognitive processes like learning and memory. 

Optogenetics and Opsins 

So what exactly is Optogenetics and how does it work? 

Optogenetics is a technology that uses light to stimulate genetically specific neurons, in that way the surrounding cells not having the genes are not stimulated. So, researchers discovered that there are some plants(e.g Bacteria) that can convert light energy into electrical energy due to their genetic makeup comprising opsin genes, that encode for opsin proteins(light-sensitive proteins) and they figured out that this ability could be replicated in neurons with the use of gene therapy to impute the genes to the desired neurons. 

So how does it work? How does an opsin gene when imputed into a neuron give it the ability to convert light energy into electrical energy? 

Genes as we know, when expressed lead to the production of proteins which could be receptors, in this case opsin receptors which are sensitive to light, and when stimulated there is

a signal transduction process that leads to the upregulation of pumps and channels that allows the influx or efflux of ions thereby changing the electrical state of these neurons. 

Potential of Optogenetics in Neuroscience 

Optogenetics has made a lot of breakthroughs in research and holds great potential for clinical practice. It has been seen in vision research that optogenetics can be used in retinal degenerative diseases(e.g. retinitis pigmentosa) to restore vision by conferring light sensitivity to distinct retinal cell types. It is currently used in various fields of Neuroscience to study the brain's circuitry both in healthy and diseased conditions. 

Conclusion 

Researchers have studied the brain better since the invention of Optogenetics as they have been able to modulate the brain's activity unlike other traditional methods of deep brain stimulation that utilize chemicals(neurotransmitters) in stimulating the brain. 

References

Duebel, J., Marazova, K., & Sahel, J.-A. (2015, May). Optogenetics. Current opinion in ophthalmology. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5395664/

Written by Ayebamiebi Yousuo from MEDILOQUY