文摘
Summary
It is broadly accepted that long-term memory (LTM) is formed sequentially after learning and short-term memory (STM) formation, but the nature of the relationship between early and late memory traces remains heavily debated []. To shed light on this issue, we used an olfactory appetitive conditioning in Drosophila, wherein starved flies learned to associate an odor with the presence of sugar []. We took advantage of the fact that both STM and LTM are generated after a unique conditioning cycle [] to demonstrate that appetitive LTM is able to form independently of STM. More specifically, we show that (1) STM retrieval involves output from ¦Ã neurons of the mushroom body (MB), i.e., the olfactory memory center [], whereas LTM retrieval involves output from ¦Á¦Â MB neurons; (2) STM information is not transferred from ¦Ã neurons to ¦Á¦Â neurons for LTM formation; and (3) the adenylyl cyclase RUT, which is thought to operate as a coincidence detector between the olfactory stimulus and the sugar stimulus [], is required independently in ¦Ã neurons to form appetitive STM and in ¦Á¦Â neurons to form LTM. Taken together, these results demonstrate that appetitive short- and long-term memories are formed and processed in parallel.
