April 20, 2012
Blind Mice, Paralyzed Monkeys, And Regenerative Medicine
New research reported this week illustrates some very interesting results in the field of regenerative medicine. Blind mice were able to see once more and monkeys with paralyzed hands were able to flex them again.
The night-blind mice, were implanted with precursor eye cells, and in tests the mice saw well enough after the procedure to swim to a platform in dim underwater light.
The monkeys studied in the research had arms which were paralyzed with nerve blocks. These monkeys were then hooked to a computer which relayed signals from their brain to their hands. These signals enabled to monkeys to once again use their arms and hands.
These techniques and more are a part of research to provide alternatives to patients who have bodies damaged by trauma or disabled by bad genes. The subsequent report has been published in the journal Nature.
Speaking to Bloomberg News, Robin Ali, an author in the blind mice study, said, “Cells in a dish is one challenge and, five to 10 years ago, that was exciting.”
“What´s interesting about these three papers is that we´re really starting to move into regenerative medicine. What these have in common is looking at repairing systems in vivo,” or in living organisms.
Ali is a molecular genetics professor at University College London and gave the night blind mice precursors of rod cells. These rod cells function best in times of low light and are almost entirely responsible for night vision. Once the cells were transported, synapses were formed, improving night vision in the mice. To test this improvement, the mice were placed in a dimly lit water maze, wherein the mice had to swim to a platform.
With this research, Ali hopes to repair all vision disorders, including color blindness.
“Most causes of blindness are due to the loss of photoreceptors,” Ali said. “What I have in mind is approaching unrealistic – I want to restore normal vision. But if we´re aiming to provide useful function, that may be achievable.”
Deepak Srivastava is the director of the Gladstone Institute at the University of California, San Francisco. He describes how different genes can be turned on and off, thus being manipulated to restore sight and lost muscle tissue, “There are large pools of cells in the heart that aren´t muscle cells, and even though they aren´t meant to be muscle cells, if we flipped the switches, we thought we could convert it,” Srivastava told Bloomberg's Elizabeth Lopatto.
Regenerative medicine works together with many other sciences like biology, chemistry, computing, engineering, genetics, and robotics to bypass the particular organ or muscle failure.
According to Srivastava, however, stem cells are just one way to approach the problems of degenerating bodies. By focusing on converting existing cells, scientists can bypass the need for costly and potentially dangerous cell transplantation and therefore lower the risk of cancer forming.
Lee Miller, a professor of physiology at Northwestern University´s Feinberg School of Medicine in Chicago, conducted his study on two monkeys who had nerve blocks used to simulate paralysis, much like the nerve paralysis seen in patients with a spinal cord injury. While previous studies had monkeys move robot arms with signals from their brain, Miller´s study used an electrical device to move the signals from the brain to the monkey´s hand, allowing them to move their hand on their own.
“The field is reaching some maturity, and we´re seeing how this could be used down the road," Srivastava said. “We´ve been working very hard the last several years, working things out in a dish. We´ve matured now to a point where we can make improvements in a whole organism, a step toward people.”