Establishment of functional neuronal circuitry relies on the activity-dependent formation of synaptic connections between neurons. Pharmacological interference with physiological patterns of neuronal activity during critical periods of brain development can have a lasting impact on network assembly and function. In this context, exposure of the developing organism to general anesthetics, acting as powerful pharmacological modulators of ligand-gated ion channels in the central nervous system, may impair brain maturation. This is a potentially important public health concern since millions of infants and young children receive anesthesia every year worldwide, and there is accumulating experimental and human epidemiological data suggesting an association between general anesthesia and altered neurodevelopment. Results obtained during the past 10 years in the host laboratory of my Master work suggest that general anesthetics acting as positive allosteric modulators of the GABAA receptor can exert lasting impact on synaptogenesis when administered during the early postnatal period. Little is known, however, about the impact of anesthetic drugs acting primarily via non-competitive pharmacological blockade of the NMDA receptor, such as Ketamine...