The taste and smell of food can evoke strong memories. The strength and importance of food learning makes it a good system for exploration of the behavior, neur ology, and molecular biology of learning and memory. I use a simple but robust model of learning: conditioned taste aversion, in which rats learn to reject a pa latable solution after it is paired with a toxin (LiCl). Behavioral studies are combined with brain lesions, neuroanatomical imaging, and single-cell RNA amplification for study of the patterns of gene expression underlying long-term changes in the rat's ingestive behavior.