Developmental and adult synaptic plasticity, regulation of gene expression during nervous system development, cell signaling and signal transduction by the TGF-?/BMP pathway in neurons. Synaptic plasticity during development requires bi-directional communication between the afferent neuron and the target cell, typically another neuron or a muscle. The signaling from target to neuron is known as retrograde signaling, and genetic analysis in the fruit fly Drosophila melanogaster has shown that growth factors of the TGF-? family are essential in this process. The projects in the laboratory center on the role of TGF-? growth factors in developmental and activity-induced synaptic plasticity. The final goal is to understand molecularly how the efficiency of synaptic transmission is regulated, resulting in synapse potentiation or depression and the appropriate behavioral correlate. A combination of genetic, molecular and biochemical approaches are used to this end, and although the favored experimental model is the Drosophila larva neuromuscular junction, other organisms and experimental paradigms are currently being considered.