This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The aim of this proposal is to understand the mechanisms by which developing inhibitory brain circuits are able to adapt to sensory inputs, and to maintain their balance with the developing excitatory circuits. During early brain development, neurons in the cerebral cortex establish connections that are then fine tuned by experience-dependent mechanisms. Although much is now known regarding processes of glutamatergic maturation and activity-dependent modification of glutamatergic synapses for network formation, postnatal development of neocortical GABAergic synapses and their role in activity-dependent modification remains unclear. The proposed research will utilize a combination of electrophysiologic recording and microscopic analyses to examine how developmental changes of inhibitory synapses and interneuron network properties are translated into a mature, functional cortical system. This research will provide new information about mechanisms of cortical development and experience-dependant plasticity. It will help us gain further insights into mechanisms underlying several developmental related neurological disorders such as cortical dysplasia, schizophrenia, epilepsy and dyslexia, in which early endogenous and exogenous unfavorable conditions create long-lasting impacts on the mature cortex.