Our focus has been on the cell biological processes that promote and maintain sensory signaling and neuronal plasticity throughout development. Neurons are the front-line of an organism’s response to its environment. Thus, understanding how their signaling components organize to perceive and transmit information both in response to novel and persistent cues is key to understanding behavior. We are testing the hypothesis that signaling pathways act via small RNAs to modify chromatin thereby allowing for experience-dependent changes in the output response. We utilize C. elegansfor our investigations because this nematode, with only 1,000 cells and 302 neurons exhibits robust behavioral plasticity and we can use cell biological, genetic, behavioral, physiological and molecular techniques to understand the molecular details that underlie experience driven changes in behavior. The molecular and cellular logic that underlies behavioral plasticity in C. elegans is likely to be utilized in the nervous system of higher organisms and humans and insight we gain from examining this nematode may inform both normal processes such as learning and memory as well as help us understand what goes awry in disease states such as addiction and perhaps attention deficit disorders. Our particular focus is on the olfactory sensory circuit of C. elegans.