A central challenge for neuroscience is determining how experience shapes the functional properties of the central nervous system. The auditory localization pathway in barn owls represents the associations of auditory cues with locations in space as neurophysiological maps. Previous research has shown that experience shapes these maps powerfully in juveniles, but has little effect in adults. Because of its exquisite precision, the auditory localization system has proven to be an excellent model for investigating the instructive role experience plays in determining neural function. The proposed research will employ behavioral, pharmacological, and electrophysiological techniques to investigate principles that govern auditory plasticity. Particular attention will be paid to techniques that increase plasticity in adults. Understanding the cellular mechanisms that underlie adaptive plasticity is an important step towards formulating optimal therapies for rehabilitation following injury to the central nervous system. ? ?