Scientists, including students, find new aspects to visual system development

Fox Lab students

By David Hungate


Aboozar Monavarfeshani, Gabriela Carrillo, and Sarah Hammer, students in the Fox Laboratory, research the retina and how it grows in the brain.

A recently published Virginia Tech Carilion Research Institute study came with a twist not often found in scientific papers. One of the first authors, who just completed her freshman year at Virginia Tech, was a high school student when she started working on the project, while most of the other authors are undergraduate, graduate, or medical students.

Sarah Hammer, the paper’s first author, was a senior at the Roanoke Valley Governor’s School for Science and Technology when she contacted Michael Fox, who had just joined the Virginia Tech Carilion Research Institute as an associate professor. Fox agreed to mentor Hammer for her senior-year project.

“When she came to the lab I knew she had extensive computer skills,” Fox said. “I soon learned that she’s also a great artist. Those skill sets made it a no-brainer for her to do complex 3-D reconstructions.”

The scientists used a high-powered electron microscope to image slices of tissue samples. Hammer studied the images, located the structures of interest, and created 3-D model of the structures.

“Once I received the electron microscopy images, I’d find retinal terminals and trace them through the stack of images using a computer program specifically designed for creating 3-D reconstructions,” Hammer said. With the 3-D model to analyze, Hammer could quantify the sizes of the terminals and compare them across different brain areas.

“This is a perfect example of how individual contributions enhance a research study,” said Gabriela Carrillo of Irvine, California, who received her bachelor’s in psychology from Virginia Tech this past spring and was also a co-first author on the journal article. Carrillo works in Fox’s laboratory, and for this project, she was responsible for preparing, imaging, and analyzing tissue samples.

“Many people were working on diverse but related things,” Carrillo said. “We pulled data from everyone and looked at everything in a different way. We had many tissue samples, and we realized we should focus on retinal terminals.”

Aboozar Monavarfeshani, a graduate student in Virginia Tech’s Biological Sciences program from Tehran, Iran, compared retinal terminal sizes in different brain areas between young and older mice. He found that terminals in young mice were roughly the same size regardless of location, but as the mice aged, the terminal sizes began to differentiate. Monavarfeshani will use this study as a jumping-off point for his doctoral thesis.

Monavarfeshani, Hammer, and Carrillo continue to work in Fox’s laboratory, studying retinal terminals in the brain and probing why these terminal endings form differently. Carrillo presented the project at the National Conference for Undergraduate Research in April, and she will present it again at the annual Society for Neuroscience meeting in November in Washington, DC.

“In this business we have papers accepted quite routinely; it’s part of our job,” Fox said. “But this paper was more fun because the students are all so young, both chronologically and scientifically. They were so excited when the paper was accepted. It was really refreshing.”

Written by Ashley WennersHerron