Our laboratory studies how neurons store a memory. Transgenic mice are used to tag neurons that are activated during memory encoding. The tag can be used to image, analyze and manipulate these neurons. Imaging tagged neurons in various brain regions provides important information on how circuits of neurons support memory storage and erasure. Tagged neurons can be analyzed for changes in gene expression, thereby elucidating molecular mechanisms of memory storage. Selective manipulation of tagged neurons can be used to control behavioral expression of a memory.