Manipulation of voltage of embryonic frog cells located in midsection of the tadpole caused the cell to develop into a working eye. (Credit: Michael Levin and Sherry Aw)
Science Daily — For the first time, scientists have altered natural bioelectrical communication among cells to directly specify the type of new organ to be created at a particular location within a vertebrate organism. Using genetic manipulation of membrane voltage in Xenopus (frog) embryos, biologists at Tufts University's School of Arts and Sciences were able to cause tadpoles to grow eyes outside of the head area.
The researchers achieved most surprising results when they manipulated membrane voltage of cells in the tadpole's back and tail, well outside of where the eyes could normally form. "The hypothesis is that for every structure in the body there is a specific membrane voltage range that drives organogenesis," said Pai. "These were cells in regions that were never thought to be able to form eyes. This suggests that cells from anywhere in the body can be driven to form an eye."
To do this, they changed the voltage gradient of cells in the tadpoles' back and tail to match that of normal eye cells. The eye-specific gradient drove the cells in the back and tail -- which would normally develop into other organs -- to develop into eyes.
These findings break new ground in the field of biomedicine because they identify an entirely new control mechanism that can be capitalized upon to induce the formation of complex organs for transplantation or regenerative medicine applications, according to Michael Levin, Ph.D., professor of biology and director of the Center for Regenerative and Developmental Biology at Tufts University's School of Arts and Sciences. Levin is senior and corresponding author on the work published in the journal "Development." online December 7 2011, in advance of print.
"These results reveal a new regulator of eye formation during development, and suggest novel approaches for the detection and repair of birth defects affecting the visual system," he said. "Aside from the regenerative medicine applications of this new technique for eyes, this is a first step to cracking the bioelectric code."
Tufts post-doctoral fellow Vaibhav P. Pai Ph.D., is first author of the paper, entitled "Transmembrane Voltage Potential Controls Embryonic Eye Patterning in Xenopus laevis." .
Signals Turn On Eye Genes
From the outset of their research, the Tufts' biologists wanted to understand how cells use natural electrical signals to communicate in their task of creating and placing body organs. In recent research, Tufts biologist Dany S. Adams showed that bioelectrical signals are necessary for normal face formation in the Xenopus (frog) embryos. In the current set of experiments, the Levin lab identified and marked hyperpolarized (more negatively charged) cell clusters located in the head region of the frog embryo.
They found that these cells expressed genes that are involved in building the eye called Eye Field Transcription Factors (EFTFs). Sectioning of the embryo through the developed eye and analyzing the eye regions under fluorescence microscopy showed that the hyperpolarized cells contributed to development of the lens and retina. The researchers hypothesized that these cells turned on genes that are necessary for building the eye.
Changing the Signals Lead to Defects
Next, the researchers were able to show that changing the bioelectric code, or depolarizing these cells, affected normal eye formation. They injected the cells with mRNA encoding ion channels, which are a class of gating proteins embedded in the membranes of the cell. Like gates, each ion channel protein selectively allows a charged particle to pass in and out of the cell.
Using individual ion channels that allow, the researchers changed the membrane potential of these cells. This affected expression of EFTF genes, causing abnormalities to occur: Tadpoles from these experiments were normal except that they had deformed or no eyes at all.
Further, the Tufts biologists were also able to show that they could control the incidence of abnormal eyes by manipulating the voltage gradient in the embryo. "Abnormalities were proportional to the extent of disruptive depolarization," said Pai. "We developed techniques to raise or lower voltage potential to control gene expression."
Electric Properties of Cells Can Be Manipulated to Generate Specific Organs
The researchers achieved most surprising results when they manipulated membrane voltage of cells in the tadpole's back and tail, well outside of where the eyes could normally form.
"The hypothesis is that for every structure in the body there is a specific membrane voltage range that drives organogenesis," said Pai. "By using a specific membrane voltage, we were able to generate normal eyes in regions that were never thought to be able to form eyes. This suggests that cells from anywhere in the body can be driven to form an eye."
Levin and his colleagues are pursuing further research, additionally targeting the brain, spinal cord, and limbs. The findings, he said "will allow us to have much better control of tissue and organ pattern formation in general. We are developing new applications of molecular bioelectricity in limb regeneration, brain repair, and synthetic biology." Additional authors include post-doctoral fellow Sherry Aw, Tufts Postdoctoral Associate Tal Shomrat, and Research Associate Joan M. Lemire. Funding for this research came from the National Institutes of Health.
“The real import of the scriptures is revealed to one who has unflinching faith in both the Supreme Personality of Godhead and the spiritual master.” (Shvetashvatara Upanishad, 6.23)
As the ancient scriptures of India are composed mostly in the Sanskrit language and its derivatives, it’s difficult to gain much insight by just picking up an old work and reading it. Finding the original Sanskrit versions of these works is also difficult. In days past, copies were made by hand, with the interested readers meticulously writing down the many verses onto leaf pages and then storing them safely within temples. Because of the austerity in production, man was more prone to remembering the many important verses, reciting them when necessary.
The statements about the soul and reincarnation form some of the more straightforward verses from the Gita, but there is still some context to be understood, some background information not available to those who only read the verses. For starters, what is the makeup of the soul? What is the purpose to activity if the soul just lives forever anyway? Why even teach anyone about these things when it seems like the position of neutrality is there by default? Whether I know that the soul is eternal or not doesn’t change the fact that my soul will live on, so why did Krishna even present this information?
But the Gita has a lot more context than this. Going ahead with one’s tasks in a fearless manner is certainly helpful, but how does one determine what the proper task is? Should I make up my own desires and follow through on them without fear? What if my desire is to steal from others? Should I go into home after home and rummage through people’s things without worrying about the consequences? After all, if my soul is eternal, what difference does it make whether or not I follow piety?
Arjuna was in Krishna’s association and after he received instruction from the Lord it seemed like he fell into the category of not being obliged to work. He was now knowledgeable of the soul, material nature, and the temporary nature of fruitive results. Armed with transcendental knowledge, he had nothing to do, yet in the end he followed Krishna’s direction and fought ahead. In this way we see that the position of neutrality is reached regardless; whether one is pious or impious. Instead of choosing the impious route on a whim, the truly wise follow Krishna’s order, for that keeps them in the Lord’s company. In Arjuna’s case, the wise instruction was provided by the Lord Himself. This is the real message of the Gita; to follow God’s orders, which are given either directly or through a representative who follows in the same mood of devotion as Arjuna.
The bona fide spiritual master incorporates the necessary context into his translations and commentaries. That these works would be valuable and presented from a position of higher intelligence shouldn’t be very difficult to understand. The first time we read or study something, we obviously don’t know much about it. But if we spend our life dedicated to learning about, honoring and becoming immersed in the particular subject matter, we will come from a much better position later on when presenting and discussing the information with others. The guru lives devotional service by regularly 
If, for instance, a verse makes reference to Prahlada Maharaja being saved or Draupadi being rescued by Krishna’s intervention, what is the reader going to know? What if a passing reference is made to the 8,400,000 different species or the fact that Ajamila was saved by reciting the name of Narayana? These statements have specific context, information that can be found elsewhere in the Vedas. Even if we were to find the specific verses mentioning these incidents and read the translations, we still wouldn’t fully understand. He who follows the bhakti discipline under the authorized guidelines, however, can fully appreciate the brilliance of these statements and even invoke the incidents when appropriate.
