Within neuroscience and related disciplines, the development of the technique known as Optogenetics is widely regarded as one of the most important breakthroughs in modern science. The ability to target certain neuronal populations with light to trigger certain behavior is the broad idea behind this technique. In the past decade, hundreds of research groups have used Optogenetics to learn how various networks of neurons contribute to behavior, perception, and cognition. From eating disorders to epilepsy, to Parkinson’s disease – the potential of Optogenetic investigations in brain-relation conditions is enormous.
The latest development within Optogenetics is a potential application in visual therapeutics. Researchers at MIT’s Media Lab have developed a red-shifted opsin that produces significantly more retinal nerve cell spiking when exposed to red light than opsins developed in the past. The red-shifted microbial rhodopsin (named ‘JAWS’) is basically an engineered chloride ion pump. These are pigments present in the retinal cells of many species that when exposed to light, move positive ions into cells to boost their activity (excitation), or move negative ions into cells to shut them down (inhibition). This phenomenon is known as neural hyper-polarization.
The researchers aimed to study the effects of Optogenetic neural hyper-polarization on mice having retinitis pigmentosa – a visual disorder that results first in night-blindness and then overall blindness as a result of photoreceptor degeneration. A potential therapy for patients with this condition is to re-sensitize the cone cells to light by introducing light-activated ion pumps in the cone photoreceptors. When JAWS was expressed in the retinal cones of retinitis pigmentosa mice, the researchers found photo-stimulation of these receptors to induce more activity in retinal cells than any previously used ion-pump. These studies may prove to be the pathways for curing different forms of blindness in people in the years to come.
The development of JAWS not only has potential in vision therapy but also in noninvasive optogenetic inhibition of neural activity. JAWS has found to be a good inhibitor of stimulus-evoked neural response in the presence of red light. This provides an area of possible research for brain-related conditions where today, surgery is the only option.
As the number of applications of Optogenetic investigations grow, more research is being done to use this technique to identify areas of the brain responsible for specific behavior and functions. While mapping the complete human brain is still years away, every day progress is being made in labs around the world- leading us one step closer to safer treatments for brain disorders and understanding the mysteries of its workings.
Share this post