Life in a lab

Researcher Tom Reh's laboratory is located on the fourth floor of the Health Sciences building. It is a spartan area, with room just barely sufficient for a handful of graduate students to fit their belongings. Two such researchers are seated in an office as Reh goes about his day.

"It's a highly variable job. I help people out when something goes wrong or they can't figure out what they're doing. In a typical day, I'm not doing as much of the lab work. I evaluate data and students' papers, make specific goals and have group meetings in the afternoons or throughout the day," Reh says.

In these meetings, he asks about various parts of the experiments and their results, including whether they achieved or came close to a certain goal or the intended results.

Reh is working with one of the graduate students, Susan Hayes, to publish the results of a recent experiment. The experiment, like most of those done in Reh's lab, has to do with whether or not stem cells inserted into the retinas of mice have been able to become regular retina cells and thereby improve eyesight.

"We study the development of the retina and how to fix it when it's broken," he says.

He points out that each person only get the chance to have one pair of retinas in his or her life; the retina, unlike most of the body, does not contain cells that can repair itself. So, he asks, "How do we fix it when it's damaged by disease and injury?"

The retina, Reh explains, is what allows us to see. The rod and cone cells within the retina do this by converting light waves that enter it into electrical impulses, or synapses, that can be interpreted by the brain. When people become blind, they are blind forever; this happens especially in people older than 65. The process is called macular degeneration, and it affects a large number of people.

"We study mouse retinal cells to see if human retinal cells will work the same way" in an attempt to reverse this process, Reh says.

Entering a dark laboratory room, Reh demonstrates the high-powered laser microscope, which he calls a two photon confocal microscope. Two large screens set up back-to-back displays of highly magnified images of a retina, which shows signs of different coloring. The colored areas are the embryonic stem cells, which have been infected by a virus to turn them either green or blue.

After examining the images, which are being saved onto a computer, Reh goes to check on the development of the human embryonic stem cells.

"This is the tissue culture room," he says, opening an incubator that contains multi-well tissue dishes with stem cells growing in them. "The cells like to be at body temperature. ... You can take the cells and put them under a microscope and watch while they are in a culture to see how they grow."

Reh and others do all the stem cell work in this room.

"Some days," he said. "they are in here isolating these cells from animals."

The cells, once grown, are transplanted by injection into the retinas of blind mice, who are anesthetized for the process. This is done once every couple of weeks when the mice are at the proper stage.

"We try to put the cells through the side [HTML_REMOVED] underneath [HTML_REMOVED] where the photoreceptors are," he says. Because a normal organism would reject such a transplant, they suppress the immune system of these mice with cyclosporin, which is put in their water. It works out fairly well, because Reh said, "It turns out that in the nervous system there is the blood-brain barrier," he says, "but there is also a blood retinal barrier which keeps the immune cells from getting in. So they're rejected less aggressively once they're in."

Reh talks about some new technology that may change part of the research process.

"We've got a fancy new microscope, so we should be able to use that now so that we don't have to take the eyes out to analyze them." Presently, however, the animals are taken to another laboratory, euthanized, and then the eyes are removed to see where the cells went.

Once the researchers have an eye to be examined, they put it in another room that contains a cryostack, a device that separates the eye into thin slices.

Reh describes this as a typical day.

"We grow our own cells and make sure the animals are happy," he says. He says he can't show the live animal testing, however, because the environment must be completely dark.

"If there's any bit of light, we want to be able to see it," he says. "We put an electrode in a contact lens [HTML_REMOVED] on the surface of the eye [HTML_REMOVED][HTML_REMOVED] which reads to a computer that records the electrical potential." If there is electrical energy being created by the eye, then the mouse can see.

"We have not been able to make a blind mouse see yet. We're pretty close [HTML_REMOVED] maybe a year away," Reh says. He describes this field as uncharted territory. "You don't know where you are; you just keep sailing."

However, he thinks he's close based on the progress made in getting the stem cells to produce rhodopsin, one protein needed for the eye to see.

"But they have to connect to the rest of the retina correctly, and they need other proteins we don't know about," he says.

If the research pans out, Reh said these cells should be implanted in people "before they've lost their rods and cones, while they're on their way, to preserve vision. Degenerated retinas are harder to repair."

He believes that the first step to correcting vision loss is to preserve the vision of those who are going to lose it.

Reach reporter Chaim Eliyah at features@thedaily.washington.edu.