In the nervous system, cell shape is malleable. Neuronal receptive endings, such as dendritic spines and sensory protrusions, are structurally remodelled by experience, and an emerging hypothesis in cellular neuroscience is that these shape changes accommodate and define changes in neuron output. Glia are the most abundant cell type in the human brain, and glia contribute extensively to nervous system disease. However, the roles played by glia in the nervous system remain largely mysterious. Several observations suggest that glia could influence the shapes of neuronal receptive-endings: they are in the right place at the right time, they can sense the postsynaptic milieu, their shapes correlate dynamically with neuronal receptive-ending cell shapes, and mutations in some glial proteins affect receptive ending shape. Researchers in this study will use a model animal system, the nematode C. elegans, to tease apart some of mechanisms leading to experience-dependent changes in behavior. They will employ powerful methods of genetic analysis in C. elegans to uncover 1) the molecular mechanisms by which glia affect neuronal shape and 2) how remodeling affects neuron function and animal behavior. Achieving a comprehensive understanding of the mechanisms that endow nervous systems with the ability to change in response to experience is of paramount importance in understanding learning, memory and other aspects of the brain. Such an understanding should ultimately allow researchers to tackle human disorders, including learning disabilities and autism, which may result from defects in nervous system plasticity.