Dr. Greenberg’s research seeks to understand how neuronal activity controls gene transcription to affect critical steps in synapse and neural circuit development. In addition to providing insight into the process of brain development, this research has contributed to the understanding of neurological and psychiatric diseases in which these processes have gone awry. This work began with the discovery that growth factors induce the rapid and transient expression of a family of genes, Immediate Early Genes (IEGs) such as c-fos, whose functions are crucial for neuronal differentiation, synaptic pruning, proper excitatory inhibitory balance, and neuronal plasticity. Dr. Greenberg’s recent studies have used genomics to identify neuronal transcripts and cis-regulatory enhancer elements that respond to changes in synaptic activity, uncovering an activity-responsive transcriptional network that regulates the complexity of the dendritic arbor, the development of excitatory and inhibitory synapses, the composition of protein complexes at the pre- and post-synaptic sites, and the production of neuropeptides that control neural circuit development. Understanding how these neuronal activity-dependent gene programs function will provide new insights into how the dysregulation of this process leads to neurological  and psychiatric diseases and, ultimately, may suggest therapies for treatment of disorders of cognitive function.