March 04, 2013
The Mystery of Sight
Blind tadpoles can regenerate nerves to gain vision from tail.
When researchers from Tufts University wanted to investigate the plasticity of the brain — how it can be pushed beyond typical usage — they turned to blind tadpoles.
And what they found was the regenerative creatures' visual capacity had a remarkable ability to adapt, reports The Scientist.
When the scientists surgically removed the eyes of the tadpole, and grafted embryonic eye precursor tissue to the tail, the grafted tissue grew into eyes (known as ectopic eyes), developing nerves that imbedded into the tail tissue.
In some tadpoles, the nerves extended into the spinal cord. None of the nerves connected back to the tadpole's brains.
The lead researchers, Michael Levin and Douglas Blackiston tested the capability of the ectopic eyes by shining a red LED light in one area of the tadpole's habitat, and a blue LED in another area. A slight electric shock was associated with the red area, "teaching" the amphibians to avoid it.
Criteria for successful learning was if a tadpole spent under 10 percent of their time receiving shocks, with a result of 70 percent of post-training time spent avoiding the red LED area.
What happened next was unprecedented. The tadpoles with nerves that reached the spinal cord could see the difference between two colors of LED lights with their new, ectopic eyes. In fact, they were the only successful learners.
Says Levin, "We showed the ectopic eyes don’t need to connect directly to the brain" to see and to learn.
Although the tadpole's brain is wired to process visual information through the optic nerve, this study shows that may not be the only way for visual stimuli to be understood. What is still a mystery to the researchers is how the brain is processing that information.
Next steps for Levin and Blackiston will be unraveling that mystery, tracking how the ectopic eyes send signals to the brain.
The research could potentially inform the development and design of functioning artificial and regenerated body parts, says neurobiologist Günther Zupanc of Northeastern University.
Although not involved in the study, he offers that the team's research will be helpful in understanding what the body needs to get the man-made limbs and organs to work properly.
Story and Photo found at : msn.com.
John 9:25 (CEV)
All I know is that I used to be blind, but now I can see.
John 9:39 (NLT)
Then Jesus told him, “I entered this world to render judgment – to give sight to the blind and to show those who think they see that they are blind.
What does today’s God’s story teach us about blindness and sight?
In this passage in John, Jesus heals a man who was blind from birth. The Pharisees could not understand how this man could now see. They sent for the man’s parents to confirm that he had indeed always been blind. And the Pharisees insisted that Jesus must be a sinner because the healing took place on the Sabbath. The Pharisees were the ones who were truly blind.
How can I connect today’s story and God’s story to my life?
In today’s news story, the scientists admit that they cannot comprehend the mystery of how these ectopic (out of place) eyes can possibly be sending signals to the brain of the blind tadpoles. It’s a thrilling admission; God’s creation is full of amazing mysteries. And as for me, I am thrilled by the Scripture passage – All I know is:
- God created me a little lower than the angels.
- He loves me so much that he sent his Son to die for my sins.
- I used to be ‘blind’ but now I can see.
- God is continually transforming me to be more like him.
How can I connect today’s story, God’s story and my story to others?
I have friends and family members who are ‘blind.’ Science stories like today’s story can be a great doorway to help connect God’s story to their stories. Scientists cannot explain every mystery, because ultimately God’s creation is beyond comprehension. I can share today’s news story with someone who appreciates the challenges and wonders of science. I can share how God has impacted my life. I can listen to their stories. And I can pray that God will open their eyes so that they can ‘see.’