We aim to identify the key molecules and their signaling cascades involved in synapse formation and functions in learning and memory and their deficits in various disease conditions. We are particularly interested in the activity-dependent signaling pathways underlying synaptic structural changes. We study different synapse types in the brain, how these synapses form, function, and been regulated. We take advantage of genetic and molecular approaches which enable accurately target the specific types of neurons/synapses located at specific brain regions (spatial control) at specific development window (temporal control) to ask that how the synapses are developmentally regulated and how this regulatory mechanism fail in the disordered brains.