I am a neurobiologist aiming to understand the molecular regulation of neuronal inhibition and brain plasticity as it pertains to mental illness and brain damage. In my PhD training, I combined molecular biology and protein biochemistry approaches to discover that protein phosphorylation of potassium chloride co-transporter KCC2 quickly modulates the efficacy of inhibitory GABA response (Lee et al., Nature Neuroscience, 2011). In my current post-doctoral research, I focus on studying how GABA-mediated inhibitory signaling determines critical period (CP) timing in early brain development. I found that the non-cell autonomous homeoprotein Otx2 serves as a ‘master regulator’ in determining GABAergic parvalbumin (PV) circuit maturation during CP. Mutations in Otx2 lead to delayed CP and altered cognitive behaviors in mice (Lee et al., Molecular Psychiatry, 2017; Spatazza and Lee et al., Cell Reports 2013). My current project investigates the impact of synchronous brain activities (gamma oscillations) on metabolic stress (redox dysregulation) and the specialized extracellular matrix perineuronal nets (PNN), which might have tremendous therapeutic values in mental illness and brain damage.