Certain genes are activated to express proteins when cells are stimulated in particular ways. Within the nervous system, one gene of current interest is known as "c-fos" and there are two possible mechanisms that may activate its expression. In some studies, high levels of activity in nerve cells apparently turn on c-fos expression. There are some other studies that indicate c-fos may be turned on instead by a change in normal levels of activity, suggesting a role for this gene in the phenomenon of neural plasticity. Such plasticity is the property that allows a nerve cell to change its output signal in relation to a given input, and is important in understanding properties of development and circuits underlying learning. This exploratory (SGER) work will utilize the known directional sensitivity of cells in the visual system, in the retina of the eye and in the brain, to see what role c-fos expression plays during specific directional responsiveness. Beyond its importance for visual neuroscience, a high impact on neuroscience in general is likely if this work develops a way of specifically staining an entire physiological class of individual nerve cells, since such direct demonstrations of structure and function are usually done one cell at a time. There is a further great potential impact on neuroscience, particularly sensory and developmental neuroscience, by clarifying how genetic expression is related to neuronal activity and plasticity.
