Many neurological illnesses including a subset of pediatric epilepsies are thought to arise during the development of the nervous system. Increasing experimental evidence points towards imbalances between the excitatory and inhibitory circuits in the brain as a prominent component in the generation of epilepsy. The goal of this proposal is to assess how environmental perturbations during a critical period of development affect inhibitory connections and lead to abnormal brain activity. We will focus our studies in a subset of inhibitory neurons since our previous work indicates that these neurons are exquisitely sensitive to environmental stress in newborns. We hope that our studies will inspire therapies to correct aberrant brain formation in epilepsy.