Mechanisms of sensory transduction and sensory information coding

Detection of external and internal physical and chemical signals are essential processes for all living things. Our research is aimed at discovering fundamental mechanisms of three important sensory modalities, mechanosensation, vision and olfaction. Understanding how these senses work would have wide implications in fields such as medicine, agriculture and robotics. We use a combination of experimental approaches that include electrical recordings, molecular biology, optical imaging and bioinformatics to discover how primary sensory nerve cells detect and process sensory signals. We are also interested in how sensory transduction mechanisms are adapted to different environments and lifestyles, if they are modulated by neurochemicals, and what kinds of information about the detected signals are transmitted to the brain.*Mechanotransduction provides senses such as touch, hearing, and balance, and is also crucial for the control of movement and functions of many internal organs. We use an invertebrate model, the spider VS-3 slit-sense organ that allows unique electrophysiological and optical access to sensory neurons during mechanical stimulation. This model was previously limited by lack of genetic and molecular data, but we have recently created transcriptome libraries of spider peripheral and central nervous systems, developed software for targeted gene assembly, and assembled genes that code all major ion channel types, including all putative mechanotransduction channel families. These new data provide the basis for our proposed experiments to identify the molecular mechanisms of mechanotransduction.*Our vision work concentrates on basic mechanisms of light detection by photoreceptors. Current models of insect phototransduction are mainly based on one species, fruit flies, but different insects have evolved to respond appropriately to their environments and lifestyles, so we want to learn how vision has adapted to these differences. There is also a missing functional link in insect photoreceptors between the detection of photons into chemical signals, and the electrical changes in cell membranes that transmit information to the next stages. We recently developed methods to silence individual genes in insect eyes and will use this technique to unravel the molecular mechanisms involved.*We are also investigating early steps in insect olfaction, an important component of their behaviour and a target for pest control and prevention of insect borne disease. We are interested in the time dependence of olfaction because it is clearly important in processes such as mate detection via pheromones, and host selection from carbon dioxide pulsation. We have invented new ways of measuring olfactory time dependence, and are using this approach to learn more about the earliest steps in odor detection, and which components of the olfaction mechanisms control overall time dependence.*