Barn owls steer Stanford researcher to clues about visual and audito...( DENVER Co- Early experiences don't jus...)

"Things that an animal learns during an early period of life can alter the brain's anatomy dramatically," said Eric Knudsen, PhD, the Edward C. and Amy H. Sewall Professor of Neurobiology at Stanford University Medical Center. Knudsen will present findings Saturday about how early experiences mold the brain of barn owls during a talk titled "The Effects of Early Experience on Brain and Brain Development," at the annual meeting of the American Association for the Advancement of Science in Denver.

Knudsen's work takes advantage of the barn owl's keen sense of hearing. These owls develop a mental map of their world that aligns the auditory world with the visual one. When the animal hears a noise at a specific location, a nerve cell in the map region of the brain fires. That same nerve cell fires when the animal sees an object at that location. The animals use this map with deadly accuracy to pinpoint the scratching and squeaking of mice at night.

In young barn owls, Knudsen has been able to alter the auditory map of the world by having the owls wear lenses that shift their visual world to the left or right. Over time, the young owl's brain compensates so that the auditory map once again coincides with the visual map. When Knudsen removes the glasses, these owls return to their original mental map of the world.

Owls that had this early learning experience are forever different from their contemporaries, Knudsen reported in a 1998 Science paper. As adults, when Knudsen puts world-shifting lenses on the owls, only those that had early experience with the lenses can adjust. "Changes in the brain that are induced by early experience result in a persistent effect that can be reused later in life," he said. Owls that lacked the early experience could not form a new mental map.

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Contact: Amy Adams
amyadams@stanford.edu
Stanford University Medical Center
15-Feb-2003