Grant: Project Grant

Evidence over the past decade using Drosophila larvae has identified a brain circuit that explains rolling, a behaviour that appears to minimize pain and/or injury in nature when a larva is attacked by a parasitic wasp, and increases its chances of survival. In recent pilot work, we found that larvae exposed to pain-inducing stimulation during development become hypersensitized to such stimulation, and that this change involves octopamine (OCT), one of many molecules known as neuromodulators that affect neuronal function widely throughout the brain. We will first clarify the neural mechanisms underlying this stimulation-dependent hypersensitivity by examining the role of OCT in pain-detecting sensory neurons. We will then investigate how OCT neurons act in motor neurons to execute behaviour. The results of this study will reveal an understanding of how OCT contributes to hypersensitization at the level of neural circuits in the larval brain. Because pain circuits in Drosophila larvae are similar to those in mammals, and OCT is the equivalent of noradrenalin, a key neuromodulator in humans, this new knowledge could potentially identify novel targets for treating both acute and chronic pain.