LARAMIE, Wyo. (AP) — C. Jeff Woodbury, a University of Wyoming zoology and physiology professor, has been studying all types of cells for decades. But more recently, Woodbury works with cells that surely stand out more than your average unit of life. It's not hard to see them — they glow.
For the past couple of years, Woodbury, along with UW doctoral student Colleen Cassidy, a Cheyenne native, experimented with genetically engineered mice to analyze certain elements pertaining to how skin cells detect directional movements. The mice host cells labeled by different fluorescent proteins taken from several species of jellyfish. Using the proteins, certain types of sensory cells were modified to illuminate upon the detection of a moving stimulus.
"In the visual system or olfactory system, the sensory cells are in the site where they interact with the environmental stimulus," Woodbury said. "In the peripheral nervous system or skin sensory system, the sensory cells actually sit very close to the spinal cord and they send out this long process out to the periphery. There's this great distance between the two and the cell bodies are clustered in each spinal level."
Woodbury compared the target cells to gumballs in a machine. By using the jellyfish proteins, researchers could look at only the yellow or green gumballs, or in this case, cells.
"It's creating a renaissance in the field," Woodbury said.
By selectively turning on the fluorescent proteins, Woodbury and Cassidy were able to see which types of sensory neurons innervate different regions of a mammal's skin. As a result, they discovered some sensory neurons are directionally selective, meaning they can detect movement in one direction, but not the other.
"Another thing is the question of how that comes about and what makes those cells do that," he said. "We were able to trace this functional property. We laid out the cellular and molecular logic for giving rise to these types of cells and what makes them develop on certain sides of a hair that then allows them to sense movement in one direction or another."
For Cassidy, the research has been a rewarding, but time consuming effort.
"To do one of these preps, it takes probably six or seven hours to get to the point where we can start gathering data," Cassidy said. "It was really a fun team effort. This really fits with me nicely because I've done a lot of work with the whisker system and figuring out how rodents actually feel with their whiskers. It's cool to take this into general hairy skin and see if the same principles apply."
Kristen Smith, a third-year doctoral student from Little Rock, Arkansas, has worked in Woodbury's lab for several years. Smith said she enjoys the difficulty of working with Woodbury and Cassidy.
"I love the technical difficulty of what we do," Smith said. "It's a huge challenge and something new happens all the time. Jeff gives us awesome independence. He wants to know the answer."
Donal Skinner, head of UW's zoology and physiology department, said Woodbury's research helps others think about sensory systems in a more progressive manner.
"Historically, there was a very linear way of thinking about things in nice little categories and Jeff's work has really shown that's not accurate," Skinner said. "The lines of communication are not purely distinct in one area. Jeff has very high standards and publishes in exceptional journals. The students that work with Jeff really thrive."
In a laboratory setting, Woodbury and his research cohort certainly solved a mystery, but their discoveries could potentially have more lasting effects in the field of pain management. The cells studied in this case are positioned closely to where pain cells operate.
Researchers have known for some time that touch can inhibit pain. With the discovery of the directional selectivity in mice, touch in one direction could inhibit pain more so than the opposite direction, but there are numerous questions still needing answers.
"If the inhibition of pain by touch is acting through these fibers that are positioned anatomically to do this, it might suggest certain directions are going to be far more effective than the opposite direction," Woodbury said. "At a finer grained level, it is also known the activation of touch fibers can release things locally in the skin and in the spinal cord that can modulate the effectiveness of pain fibers firing because of some injury, so there are a number of things to go in and find more about that could help us predict improvement in therapeutic trials."
Information from: Laramie Boomerang, http://www.laramieboomerang.com