Touch sensation in the skin is accomplished by a heterogeneous variety of nerve cell subtypes that are each specialized to sense different kinds of touch stimuli, including temperature, pressure, and chemicals. Activation of each cell type elicits distinct perceptions and behavioral responses that are appropriate for the particular stimulus. This observation implies that each touch cell subtype connects to a distinct neural circuit in the brain. This project will investigate how particular features of touch-sensing neurons are specialized for their sensory function. To accomplish this, they are using zebrafish larvae as a model because they have a simplified nervous system, their optical clarity allows direct imaging of cellular morphology, and they are amenable to a wide variety of molecular and cellular manipulations. The PI has identified a unique class of touch-sensing cells in zebrafish that connect to a distinct part of the brain; whereas most touch-sensing nerve cells connect to circuits in the hindbrain, this particular subtype connects to spinal cord circuits. The project will use live imaging techniques to determine whether these cells possess other distinctive morphological features, to use molecular techniques to determine whether they express a distinct set of genes, to identify the stimuli that they sense using live physiological techniques, and to determine what behaviors they elicit by specifically activating them and monitoring the animal's behavior. Together these experiments will provide insight into how a sensory cell's particular morphological and molecular features are optimized for their functions. This project will be headed by a graduate student. Several undergraduates will also participate on different aspects of the project, providing them with a rare opportunity for exposure to basic neurobiological research.
