Our behavior reflects neural circuits sculpted by experience during “critical periods” in postnatal life. Such heightened plasticity declines into adulthood, often limiting recovery of function. On the other hand, the adult brain needs stability. Failed stabilization can disrupt circuit computations by allowing modification by undesirable information, which may lead to mental disorders. How does the brain solve this stability-plasticity dilemma? The goal of our research is to identify the mechanisms of developmental critical periods to establish (1) perception and (2) cognition relevant to neurodevelopmental and psychiatric disorders. We take an integrated approach combining molecular, anatomical, imaging, electrophysiological, and behavior methodologies using mouse models. In my talk, I will first discuss our recent findings of a novel nicotinic regulator of inhibitory neuron activity to restore juvenile-like plasticity in adult visual cortex. Next, I will share results of our recent project aiming to examine to what extent a mechanism critical for regulating the critical period for visual cortex development also modulates maturation of frontal cortex-dependent cognitive functions such as attention.