This Tadpole Sees the World Through an Eyeball Surgically Grafted to Its Tail

Douglas Blackiston & Michael Levin/Tufts University

Scientists have restored vision to blind tadpoles by surgically implanting eyes onto their tails, and treating the augmented animals with a drug that boosts nerve growth.

While the gruesome transplant procedure sounds a little like the work of mad scientists, the technique could help pave the way for using complex bioengineered organs in humans – especially since the drug involved is Zolmitriptan: a compound that activates serotonin receptors and is already used to treat migraines.

The research is important because it tells us more about how nerves from transplanted organs can be used to connect with the central nervous system. As such, the findings could impact everything from organ transplants to learning how nerves can regenerate after injury. 

But a word of warning – the process does involve some pretty grotesque and cruel-sounding procedures conducted on tadpoles.

With that said, to see just how malleable the tadpole sensory system is, Levin's team took early-stage tadpoles at just three days of age, removed their eyes, and cut narrow slits in their tails. Into these slits they then grafted eyes from other three-day-old tadpoles.

"These are embryos, so they are Play-Doh consistency," one of the researchers, Douglas Blackiston, told Eric Boodman at Stat.

The findings are reported in npj Regenerative Medicine.