Journal Express, Knoxville, IA

Community News Network

March 4, 2013

Can eyes see outside of the head?

PITTSBURGH — Recently, we have witnessed remarkable, fictional-sounding advancements in science and medicine. There's a guy who can hear color, another with a bionic eye attached to his brain, and a woman fighting back against the debilitating symptoms of multiple sclerosis by placing electrodes on her tongue. But for our next trick, we're going to need a bucket of tadpoles with eyes on their butts and some good old-fashioned alternating current. In other words, things are about to get all kinds of weird.

There's a great deal of wow to unpack here, so let's take it piece by piece. Using embryos from the African clawed frog (Xenopus), scientists at Tufts' Center for Regenerative and Developmental Biology were able to transplant eye primordia — basically, the little nubs of flesh that will eventually grow into an eye — from one tadpole's head to another's posterior, flank or tail. They don't play around with nerve endings or "wiring" or anything like that. They just cut out the cells from the head, slice open a bit of the tail, and jam them in.

As the eyes grow, they send out snaking tendrils of nerve fiber, or axons. We know this because the "tissue donor" tadpoles — a term that makes it sound like they had a choice — were injected with tdTomato, a fluorescent red protein. This allowed the researchers to watch innervation, or nerve growth, as it happened. Of those eye primordia that sent out feelers, nearly half hardwired directly into the spine, while the other half built connections to the nearby stomach. None of the tadpoles grew tdTomato-marked pathways to the brain.

Before they could test the ectopic eyes however, the native ones had to be severed and removed. Otherwise, how would the scientists know which of the tadpole's three eyes was truly seeing? (Note: Severing optical nerves sounds like nasty business, but even these partially-developed tadpoles received anesthesia via fish sedative. Wounds healed completely within 24 hours.)

Text Only
Community News Network
Features
AP Video
Raw: House OKs Bill for Border Crisis Funds Rare Whale Fossil Pulled From Calif. Backyard Denver Celebrates Pot at the County Fair Escaping Email: Inspired Vision or Pipe Dream? Obama Calls on Hamas to Release Israeli Soldier Hispanic Caucus Slams GOP for Border Bill Shifts Obama: GOP Not Even Trying to Solve Immigration Emory Prepares to Treat American Ebola Cases US Employers Add 209K Jobs, Rate 6.2 Pct House GOP Optimistic About New Border Bill Four Rescued From Crashed Plane Clinton Before 9-11: Could Have Killed Bin Laden Couple Channel Grief Into Soldiers' Retreat WWI Aviation Still Alive at Aerodrome in NY Raw: Woman Who Faced Death Over Faith in N.H. Russell Simmons, LL Cool J Visit Youth at Jail Raw: Obama Gets Hug From Special Olympian US, UN Announce Deal on Gaza Cease-Fire Despite Moratorium, Detroit Water Worries Remain Faith Leaders Arrested at DC Deportation Protest
Facebook
Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Poll

Upon completion and reopening of Third Street, should the City of Knoxville wait to start the next stage of the Streetscape and Infrastructure project until 2015?

Yes
No
     View Results