How to build a brain for learning? As adults we constantly face challenges in our environment and must adapt our brain circuits to deal with new situations. By splicing the DNA that codes for fluorescent proteins found in jellyfish and corals into the genome of mice, in combination with state-of-the-art multiphoton laser-scanning microscopy, we visualize and track the circuit changes that occur in the brains of awake behaving animals as they learn new skills. How to build a circuit for learning in the first place? The process of circuit assembly itself is finalized during the transition from childhood to adolescence, and influenced by experience. Construction must proceed correctly for further adult learning to occur. By comparing and contrasting learning in the young versus adult, we hope to identify, and ultimately rescue, the essential aspects of circuit construction that are vulnerable to deprivation and disease. The specific goal of my research is to understand the influence of cortical inhibitory circuits on sensory development and perceptual learning. I use a range of techniques, including electrophysiological recordings of targeted cell types in-vivo and in-vitro, 2-photon microscopy, behavioral methods, and computational analyses.