The human genome is massive, and it contains many highly repetitive sequences that confounded researchers for years. Many of these repeats were simply written off as junk DNA that had no function. However, new research is revealing that many of these regions are much more important than we thought. Some of the repetitive portions of the genome are known to be human endogenous retroviruses (HERVs). These sequences originated from viruses that infected human germ cells millions of years ago and affected our evolution. About eight percent of our genome is thought to be made up of HERVs. These HERVs have also been associated with a variety of psychiatric disorders, although the connection is unclear.
A new study reported in Nature Communications has suggested that HERVs are making a significant but unappreciated contribution to the development of psychiatric disorders, and that they may help explain a genetic component of these disorders that is thought to exist but has not yet been identified.
Retinitis pigmentosa and macular degeneration lead to photoreceptor death and loss of visual perception. Despite recent progress, restorative technologies for photoreceptor degeneration remain largely unavailable. Here, we describe a novel optogenetic visual prosthesis (FlexLED) based on a combination of a thin-film retinal display and optogenetic activation of retinal ganglion cells (RGCs). The FlexLED implant is a 30 µm thin, flexible, wireless µLED display with 8,192 pixels, each with an emission area of 66 µm2. The display is affixed to the retinal surface, and the electronics package is mounted under the conjunctiva in the form factor of a conventional glaucoma drainage implant. In a rabbit model of photoreceptor degeneration, optical stimulation of the retina using the FlexLED elicits activity in visual cortex. This technology is readily scalable to hundreds of thousands of pixels, providing a route towards an implantable optogenetic visual prosthesis capable of generating vision by stimulating RGCs at near-cellular resolution.
