Place: 4274 Chamberlin (Refreshments will be served)
Speaker: Kate O'Connor-Giles, UW Department of Genetics
Abstract: Neural function requires effective communication between neurons and their targets at synapses. Thus, the proper formation, growth and plasticity of synapses are critical to behavior. Despite this, the mechanisms that determine synapse size and complexity remain poorly understood. The Drosophila larval neuromuscular junction (NMJ) has become a powerful model system for dissecting the molecular mechanisms that regulate synaptic growth. Drosophila NMJs are dynamic structures that coordinate their size and strength with muscle growth and undergo changes in morphology and physiology in response to environmental stimuli and altered levels of activity. These processes depend on intercellular communication between neurons and their muscle targets. A retrograde (muscle to neuron) transforming growth factor (TGF-b/BMP) signal is required to promote synaptic growth, homeostasis and stability at NMJs. We have recently found that neuronal responsiveness to this signal is modulated by a presynaptic endocytic mechanism. This additional level of regulation underscores the high degree of molecular control over synaptic growth and highlights the importance to the organism of getting it right. I will present recent insights from studies at the Drosophila NMJ that have increased our understanding of how this complex task is achieved.