A neuron (red) grows along a microfabricated adhesive surface (green). The ability to make patterns limited only by imagination allows scientists to test what kinds of features in the extracellular environment stimulate cell growth.

Microfabricating a trellis to study neuron development

Individual brain cells accomplish an amazing feat during development. They must make two different kinds of specialized branches, called axons and dendrites, to transmit and receive information respectively. Then, they must build precise neural circuits with other cells by extending these axons and dendrites to the right places. Axons, for example, may grow millimeters away from the cell body to connect with other brain regions, and the dendritic tree might extend for hundreds of microns as well. Too few or too many branches, or branches in the wrong place can cause serious neurological problems. So, how do these cells know when and where to make a branch?

Observing living neurons as they grow in cell culture can provide some clues as to how these specialized cells develop. For example, neurons can be cultured on glass coverslips, and their behavior observed with the microscope, like looking through a window to watch the cells grow. Being able to observe cells over time allows scientists to see transient events that would otherwise go undetected, and provides much more information than studying an image from only a single moment in time.

One limitation of these traditional cell culture experiments, however, is that the cells are sprinkled over the coverslip randomly. Because the environment in which the cells grow is homogeneous, this method does not model the kinds of extracellular patterning that guides how neural circuits are built in the brain. Together, a uniform environment and random organization of the cells make it impossible to predict when or where growth will occur.

At Whitman College, a traditional liberal arts college, undergraduates in Prof. Ginger Withers’ lab are working across the disciplines of engineering and neuroscience to address this problem. Thanks to support from Withers’ NSF CAREER award and collaboration with the NSF Nanobiotechnology Center (NBTC) at Cornell University, Withers and her students are using tools of nano/microfabrication to construct patterns of growth-promoting molecules onto glass coverslips to act like a micro-trellis that can guide cell growth.

In a report that appeared in the September issue of the Journal of Neurobiology, Withers and collaborator Gary Banker, from Oregon Health and Science University, combined this microfabrication approach with live cell imaging, to analyze neurons as they grew along the trellis. When neurons were grown on a grid of thin lines, they extended branches that followed the path. But in analyzing the movies, Withers and Banker were surprised to find that even just changing the shape of the pattern, for example switching from a line to a circle, caused dramatically different behaviors. These movies showed that the growing tip of the axon could detect simple 2-dimensional changes in features of the environment. By observing how growth was altered as branches encountered different patterns, they were able to begin to tease apart the rules that govern cell growth and branch formation, making this the first project to combine nanofabrication, nerve cell culture, and live cell imaging to ask how encountering different molecules or geometric patterns can guide neuron growth.

Now, Withers and her students are using a similar microfabrication approach to ask how patterned cues in the extracellular environment can influence the growth and orientation of the earliest branches as they form from the cell body. “Our interactions with the NSF-NBTC allow us to translate state-of-the-art nanofabrication tools to address basic problems in biology, like how cells get their shape,” said Withers. “To be able to do this kind of innovative work in an undergraduate setting teaches our students the importance of integrating knowledge across diverse disciplines like engineering and neuroscience. It melts the boundaries between traditional scientific disciplines to create a new research approach where we are limited only by what we can imagine.”

Whitman undergraduate Marisa Claire Mumford presented her research on how micropatterning can alter the formation of the dendritic arbor at the 2006 Annual Society for Neurochemistry Meeting in Portland, OR.

Previous Years

NSF:

Career Award #0135985, Imaging mechanisms of dendritic development in the living neuron, PI, Ginger S. Withers ($549,995, 5 years) RECENT NEWS STORY: Whitman College Professor Wins 550,000 NSF Grant

NIH/NIEHS:

Grant #: 1 P42 NS10338 Hazardous chemicals and brain developmental plasticity, PI, Christopher S. Wallace ($750,000, 5 yrs)

Keck Foundation:

Molecular Life Sciences Initiative: Bringing Integrative Biology to Undergraduates, Whitman College ($340,000) RECENT NEWS STORY: Whitman receives $340,000 grant from Keck Foundation

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News release date: Thursday, Feb. 6, 2002

Professor brings "majesty of the living cell" to Whitman students

WALLA WALLA, Wash. -- Assistant professor of biology Ginger Withers is a new generation of biology professor. As an undergraduate she studied cells the traditional way -- looking at textbook "cartoon" figures of a circle with a nucleus. As a post-doc researcher and now at Whitman, she interacts with and makes movies of real cells -- growing neurons, swimming paramecia and other microscopic living matter to bring to her students "the majesty of the living cell."

Withers has been awarded a National Science Foundation CAREER Award of $550,000 to be used over a five-year period. The grant, given to faculty members early in their careers, is meant to encourage professors to develop new teaching approaches in the classroom while maintaining an active and state-of-the-art research experience, said Withers, who argued in her application that although she would be working with a smaller number of students at Whitman the award would have a higher impact here because of the caliber of Whitman students.

Withers, whose cutting-edge research on dendrite growth in brain cells could help advance our understanding of neurological disorders such as mental retardation, Parkinson's disease and learning disabilities, plans to use the grant to "introduce Whitman students to the living cell." Now that researchers can sequence entire genomes, says Withers, it is vital to train new scientists to place this genetic data in the context of the living system. "From the time I started working with live neurons (as a post-doc at the Oregon Health Sciences University in Gary Banker's lab) I've been blown away by the majesty of the cell. I don't think you can truly appreciate the cell until you have the opportunity to encounter its living machinery and see beyond the cartoon view you get in a textbook."

This static textbook view of the cell will soon be a thing of the past in Whitman biology classes. Withers plans to use funds from the CAREER grant (and some from a recent Keck grant to Whitman) to build student imaging work stations to complement her state-of-the-art work station. By combining resources from Whitman and funds from her grant, she was able to purchase a $100,000 microscope with live cell imaging facility that allows her to do cutting edge-research of the same quality she did at OHSU. With Keck monies she will be able to put together four student stations that will include adaptors so cameras can attach to the microscope, digital cameras (some capable of video streams) and accompanying computers. Withers said she hopes to have some of the stations put together in time for use this semester.

Withers, who is in her second year at Whitman, shares a teaching position with her husband, Chris Wallace. Last year, before funding of CAREER or Keck grants, the two biology professors teamed up in Wallace's developmental biology class to create a time-lapse movie of a living cell. Without the proper equipment, it was tricky, but Withers and Wallace thought the experience was important, and they persevered. They not only brought a television, VCR and video camera into class, but they hooked up a hair dryer to keep the cell warm -- and alive -- and managed to film the cell growing. "It was great -- but really hard to do. It's so much easier in the lab when you have the right equipment."

Wallace and Withers' teamwork includes an ongoing research project at OHSU, for which Wallace is the principal investigator. The focus of this project is to develop methods that can detect effects of low level exposure to neurotoxins in the developing central nervous system. With that project and the one NSF is funding at Whitman, "I don't really have time to do any additional research." That is why, she added, she and Wallace enjoy the shared teaching position -- it gives them half of their time to do research and half to teach. "Of course, we're not here half time; we're here all the time, so it works out well for the students, too."

As her research, funded by the CAREER grant, goes forward it creates more opportunities for students to work in her lab and gives her the flexibility to bring more of her research into the classroom, said Withers. Eventually she sees the opportunity for students to have hands-on experience manipulating living cells in all of her courses. The life sciences and the work she and Wallace do are changing rapidly and "We need to train our students to work across the border of traditional scientific disciplines. Integrative, interdisciplinary thinking is what will be required to solve the next generation of scientific problems."

Whitman students, she said, are up to the challenge. "They are fantastic, positive and insightful. Every student in my neurobiology class somewhere along the line has asked a question that I thought was profound or insightful -- they dove to the crux of the issue. It's exciting to work with students who really get it and are going to do something with it. I'm very glad to be here."

CONTACT:

Lenel Parish, Whitman News Service, 509-527-5156
Email: parishlj@whitman.edu

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Whitman receives $340,000 grant from Keck Foundation

WALLA WALLA, Wash. -- The W.M. Keck Foundation of Los Angeles, California, has awarded Whitman College a $340,000 grant to incorporate a post-genomic, integrative biology perspective into the life sciences at the college.

The W.M. Keck Foundation is one of the nation's largest philanthropic organizations. Established in 1954 by the late William Myron Keck, founder of The Superior Oil Company, the Foundation's grant making is focused primarily on the areas of medical research, science, and engineering.

"We are grateful and pleased that the Keck Foundation has awarded us this generous grant," said Whitman College President Tom Cronin. "Whitman is committed to providing the highest quality facilities and educational experiences possible for students. To this end, the college recently embarked on a major capital project of more than $20 million to construct a new 36,000 square-foot science building and to renovate the existing 77,000 square foot building."

"This grant from the W.M. Keck Foundation will enable Whitman to bring the new tools and techniques of post-genomic, integrative biology into our curriculum through coursework, laboratory experiences, student/faculty research projects, state of the art scientific equipment and lab technical support," added Pat Keef, dean of faculty.

Dan Vernon, associate professor of biology and the primary science writer on the grant proposal, said he was pleasantly surprised when he received approval of the grant. He's grateful that the Keck Foundation recognized the merit of Whitman's proposal even in tough economic times. "Without the computers and imaging equipment this grant will provide, students wouldn't be introduced to what they'll soon encounter in the real world." The decoding of plant and animal genomes has provided an explosion of raw data for biologists, said Vernon, but this is just a first step, the start rather than the finish. "Many of the big questions in biology in the next couple of decades will focus on genomes and gene function, and we're updating our curriculum to meet the challenges of teaching our students this post-genomic biology."

Assistant professor of biology Ginger Withers, who recently won a prestigious National Science Foundation CAREER AWARD to help her develop new teaching approaches while actively maintaining her research, said her work will benefit greatly from the Keck Foundation's award. Keck funds will allow her to put together four student research stations that will include adaptors to attach cameras to microscopes, digital cameras (some capable of video streams) and accompanying computers. Last semester when she and fellow assistant professor Chris Wallace created a time-lapse movie of a living cell, they resorted to using a television, VCR, video camera and hair dryer to create a movie of a moment in the life of a cell. "It was great, but really hard to do," says Withers. "It's so much easier in the lab when you have the right equipment."

Now that researchers can sequence entire genomes, adds Withers, it is vital to train new scientists to place this genetic data in the context of the living system. Withers, whose cutting-edge research on dendrite growth in brain cells could help advance our understanding of neurological disorders such as mental retardation, Parkinson's disease, and learning disabilities, agrees that the field of life sciences is changing rapidly. "We need to train our students to work across the border of traditional scientific disciplines. Integrative, interdisciplinary thinking is what will be required to solve the next generation of scientific problems."

CONTACT:

Lenel Parish, Whitman News Service, 509-527-5156
Email: parishlj@whitman.edu