University of Miami Miller School of Medicine -- Photo by John Zillioux
Mary Bartlett Bunge, a distinguished scientist at the Miami Project, thought about retiring after 57 years at the bench. Last year, she decided not to participate in the three-year renewal proposal for the Reeve Foundation International Consortium on Spinal Cord Injury; she had solidified her plans to retire by the end of 2010. Her Consortium colleagues threw her what they thought was a retirement party.
"Can I just say I'm not retiring?" says Dr. Bunge. "There is a graceful time to retire and I don't think it's quite as close as I thought it was. I'm just working, hopefully a little bit less." She says she's cut back to 75 percent. "I have a new postdoc in my lab. I'm continuing some studies because there are things that I still want to do and I still am energetic and have a passion to try and do something more."
One of the loose ends Dr. Bunge wants to tie up is a pending clinical trial for spinal cord injury using a combination of treatments including Schwann cells, a type of support cell in the nervous system that she has studied over most of her career.
This article, then, is not a retirement notice. It is a tribute to Dr. Bunge and a thankful appreciation for her many years of work with the Consortium.
Mary Bartlett was interested in science at an early age. "I used to row a small leaky rowboat along a stream in front of our house and look at all the wildlife, particularly the tadpoles and the very tiny frogs. That inspired me to wonder how the development occurred from tadpole to frog."
She might have been a fashion designer. "I used to design and make my own clothes before I went to college so fashion design was a possibility. I was also interested in child psychiatry but biology won out. I was thinking that's something I cannot do on my own. I could make clothes on my own. But I could not get into biological studies on my own so I decided I needed training for that."
After high school Dr. Bunge took college courses to become a laboratory technician. A summer course at Jackson Laboratories at Bar Harbor "changed the course of my life. One day we put rabbit heart muscle into tissue culture and I saw it beating. I didn't want to be a technician. I wanted to get into research."
Dr. Bunge went to graduate school at the University of Wisconsin, at the invitation of Dr. Robert Schilling. They worked on projects and published papers related to intrinsic factor and gastric juice. "I saw him recently. He's now 90 years old, still working. He said that our papers published in 1956 and 1957 are still highly regarded. But I wasn't really interested in gastric juice." She received her masters in Medical Physiology.
"In the meantime I had taken this course in cell biology with Dr. Hans Ris and had looked at images in the electron microscope. That was another inspirational, defining moment. We were using one of the first electron microscopes in the United States; we had to hammer the lenses into place. But still the images were just captivating."
As a graduate student Dr. Bunge took courses with medical students. This is where she met Richard Bunge. "There was this lanky looking guy. I used to sit in the front row and he sat in the front row at the other end. Then, for a summer Richard worked in Dr. Schilling's lab, on blood samples in the cold room. I didn't see him during the day. Then at 5 he would vanish into the hospital cafeteria where he washed dishes to help support himself while in medical school. I thought, this guy needs fresh air. I invited him to go sailing and that's how we got to know each other. When the wind died down in the middle of Lake Mendota we had wonderful long conversations. Dick was going to medical school so he could be a missionary; his hero was Albert Schweitzer."
Back on campus, Dr. Bunge began what was to be a lifelong collaboration with Richard, who had changed his mind about being a missionary in favor of research. Between getting her masters and her Ph.D., Mary and Richard were married. "He really introduced me to neuroscience. From grad school on, we worked together." They demonstrated that myelin could be reformed in the mature mammalian spinal cord. "When I put a section of kitten spinal cord into the electron microscope, there in the first area of the first section I looked at, was an image like the old fashioned ice tongs with the oligodendrocyte cell body at the top and two cytoplasmic arms coming off the cell body and it was forming myelin at the end of each arm. And that's how I discovered that the oligodendrocyte was the cell that made the myelin sheath for the central nervous system. That was one of my big moments in research."
Dr. Bunge says her husband became interested in nerve tissue culture and wanted to go to New York to study with Dr. Margaret Murray at Columbia. "She helped develop the techniques for nerve tissue culture and was able to achieve myelination in culture." Fortunately, there was an electron microscopy lab at Columbia headed by Dr. George Pappas. Very little work had been done to look at the detail in these tissue cultures. "Again we were looking at myelination; actually Dick and I were the first to describe synapse formation in tissue culture."
Martin Schwab, Mary Bunge, Lisa Schnell, on the occasion of Mary's 'retirement' party.
In New York the Bunges had two sons, Jonathan and Peter. Mary Bunge continued part time in the lab. The family left Columbia in 1970 for Washington University School of Medicine in St. Louis. Dr. Bunge continued to balance lab work and family life and also began to teach; she became a full professor in 1978.
The Bunge lab continued in the area of myelin repair. Says Dr. Bunge, "Rather than take a piece of tissue and try to see how much differentiation we could achieve, the Margaret Murray approach, we wanted to separate the cells in the peripheral nervous system. With Dr. Patrick Wood, we could grow neurons by themselves, the Schwann cells by themselves or the fibroblasts from peripheral nerve by themselves. Then we could prepare different combinations and observe a number of important interactions that occur between these cells, not possible in an animal."
Much of the work in St. Louis was directed toward multiple sclerosis, which is characterized by myelin loss. "Even though Dick and I were really basic scientists, we always were interested in how we could translate -- that word wasn't used at that time -- how we could extend our basic science results to help repair a deficiency or degeneration in the central nervous system."
The Bunge lab had begun some Schwann cell transplantation projects in a spinal cord injury model when Richard got an invitation in 1988 to be scientific director at the Miami Project.
"We realized that moving to Miami would be a better opportunity for us to continue our work in the spinal cord and to pursue our interest in repairing the central nervous system. We needed to build a bigger team to do this."
The Bunge lab at the University of Miami became one of the preeminent SCI labs in the world. In 1993 Richard Bunge was invited to join the Reeve International Consortium on Spinal Cord Injury. Soon thereafter, however, he became ill with esophageal cancer (he died in 1996). Mary Bunge took his place in the Consortium. "It has been a remarkable and beneficial and exciting opportunity for me for which I am extremely grateful." Dr. Bunge says the collaborative approach of the Consortium is essential. "Because we're dealing with such a complex problem, we have to think of combination strategies. I don't think any one of us is adept at all the techniques that need to be used to solve this very complex problem. I have a number of papers with other members of the Consortium. It's been wonderful."
-- Sam Maddox