College: Hunter College
Awards: National Science Foundation Graduate Research Fellowship, 2013
Putting Things in Context
Context alone can bring back memories. Walking through a sunny park might make you think of a joyous summertime picnic. On the other hand, a movie with a happy scene of companionable drinking in a bar might trigger a recovering alcoholic to crave a drink.
“One of the last frontiers in all of biology is uncovering which neural components make up a memory,” says Meryl Horn (Hunter College, B.A. in biology, 2012). Now in a doctoral program at the University of California-San Francisco, she intends to use her 2013 National Science Foundation Graduate Research Fellowship to get a better understanding of how memory works. The $126,000 grant is the most prestigious award for graduate study in the science, technology, engineering and mathematics (STEM) fields.
She decided to pursue her interest in science when she was a receptionist across the street from Hunter College – after she had earned a baccalaureate degree from Clark University in international development and social change.
In her first year, when she was working full time, she encountered associate professor Roger Persell, who was teaching an honors introduction to biology class.
“I read papers on learning and memory, saw how researchers measure memory using behavioral tasks in rodents and realized that I could study this a long time,” she recalls. “In neurobiology, I found the perfect combination of hard scientific rigor that was missing in international development, as well as the opportunity to ask questions about the mind and how the brain can encode and retrieve memories. That’s when I realized I wanted to do a Ph.D.”
She got into research in the laboratory of assistant professor Carmen V. Melendez-Vasquez, who studies the formation of the myelin sheath that surrounds nerve fibers. Horn spent three years in her laboratory, during which she co-authored a paper investigating the molecular mechanisms behind the formation of myelin in the peripheral nervous system, which is outside of the brain and spinal cord.
At UC-San Francisco, Horn switched her field of research to learning and memory. Now studying with neurology professor Patricia Janak, who holds an endowed chair in addiction research, she intends to use her NSF grant to look at how the brain’s circuitry that controls contextual memory can be altered in drug-addicted animals.
For example, a rat that is addicted to cocaine might be trained to push a lever in a box to get a dose. If it is later put back in the box, even after it has been weaned from the drug, it is likely to press that lever again and again.
“The hippocampus is important for forming contextual memories, but it’s not clear how it later retrieves them,” Horn says. She intends to use optogenetics – a technique that uses light to control the activity of a specific population of neurons in living tissue – to stimulate neurons in regions targeted by the hippocampus to figure out which target region is responsible for making the rat push the lever when placed back in the box.
“The fact that a context brings back memories is very relevant to human behavior,” she says. “For addicts, contextual cues can trigger processes that lead to relapse, and can thus be detrimental to their recovery.”