EAGER: A1 neurobiological basis of emergent perceptual learning

Successful interactions with the environment require some change in behavior to stimuli when their significance changes. Higher neuronal responses have been documented in several brain regions to a significant stimulus, compared to presentation of a non-consequential stimulus. A brain region involved in hearing and that undergoes profound changes (plasticity) during learning about the significance of sensory stimuli is the primary auditory cortex (A1). The experiments of this proposal will begin to reveal the molecular machinery allowing tone-guided behavior and learning-induced plasticity in A1 as rats learn to collect food reward after hearing a tone. It will use a combination of established and cutting edge methods: behavior, to assess learning in rats, will be combined with optical blood flow imaging to identify parts of A1 that respond to a reward-predicting tone and to one that does not, with Arc antisense oligodeoxynucleotide intracranial infusions in A1 to prevent synthesis of Arc protein specifically in A1, and with electrophysiological recordings to assess A1 neuronal responses to tones. It is predicted that rats with suppressed levels of Arc in A1 will learn to collect a food reward after hearing a tone, but will perform poorly the next day. In addition, learning-induced plasticity in A1 is expected to be impaired. To control for non-specific effects of the infusions, the project will compare the behavior and electrophysiological responses to those of rats that have received a scrambled version of the oligodeoxynucleotides. The findings will contribute to understanding the molecular underpinnings of auditory learning and consolidation of associated A1 plasticity. This research will help scientists at the undergraduate, graduate and postdoctoral level acquire highly integrative thinking and skills. It will also establish, by collaborating with local minority-serving colleges, a website for neuroscience education with grade-appropriate content for students K8-college, including those with hearing impairments.