To try and treat blindness, scientists have successfully transferred a portion of a human brain into a rat’s brain.
The University of Pennsylvania researchers said that the organoid transplant, which is basically attaching artificially generated human brain tissue to the damaged brain of a rat, offers a way to treat severe brain injuries and reverse blindness in humans.
Their findings have been published in the Cell journal.
About the new research, neurosurgery professor Isaac Chen said that “We focussed on not just transplanting each individual cell, but also transplanting tissue. Brain organoids have detailed architecture; a structure that looks like the brain. We were able to observe individual neurons within this structure in order to gain deeper understanding of the integration of transplanted organoids.”
The researchers introduced fluorescent-tagged viruses into the rat’s eye to observe which synaptic path the viruses took in order to determine just how successfully the organoid integrated into the rat’s brain.
The fact that the fluorescent substance traveled from the retina to the freshly implanted organoid indicates complete functional integration.
The scientists next examined the rat’s eyesight using pictures and flashing lights, and they found that about 25% of the human neurons that had been implanted responded to the simulation.
Chen went on to explain that “We discovered that a significant number of neurons within the organoid reacted to specific light orientations, which gives us some evidence these organoid neurons were able to integrate with the visual system as well as adopt very specific functions of the visual cortex. We weren’t expecting to see this degree of functional integration this early.”
“Whether these entities are able to integrate with the host brain networks in the context of the damaged adult mammalian brain wasn’t well established. Here, we provide some structural and functional evidence that human brain organoids can successfully integrate with the rat visual system after transplantation it into large injury cavities in the visual cortex,” the study says.
To discover if the procedure can be used to treat other kinds of brain damage, the researchers now intend to investigate how organoids may be employed in other regions of the cortex.