Salm 9514574 The ability of the cells of the brain to reorganize in response to physiological stimuli is known as plasticity. Plasticity has been shown to occur in neurons and the support cells of the brain, also known as glial cells. In response to changes in the local environment, glial cells change shape and their connections to respond to the demands placed upon them. However, the mechanisms involved in eliciting the changes of the glial cells is currently unknown. Dr. Salm is investigating the mechanisms by which glial plasticity occurs in a specific region of the brain. In this region, dehydration is a powerful physiological stimulus and it produces marked rearrangements in the cellular structure and function within the region. Whether this stimulus causes glial death, or growth is to be explored, as are other structural changes in the region. This study will provide a more complete understanding of the relationship between the environment and the function of the brain. This basic relationship ultimately forms the basis for an animal's behavioral response to its environment, including the human animal.