Our research focuses on the control of neuronal-circuit molecular organization during plasticity and learning, particularly how physiological processes signal proto-oncogenes activating phenotypic genes for altering neuronal synapses. Using physiological and behavioral stimuli and pharmacological agents, we experimentally modify the nervous system and analyze the resulting structural and molecular changes in neurons. Numerous proto-oncogenes are normally expressed in the central nervous system. These signaling genes generate proteins, e.g., kinases and phosphatases, that directly turn on or off specific molecular functioning and signal gene expression. Plasticity and learning involve sustained modification of molecular organization, which occurs through semi-stable circuitry components and modulatory systems.