19Experience-dependent plasticity in the central nervous system allows an animal to 20 adaptively change their responses to stimuli over different time scales. In this study we 21 explored the different time frames and mechanisms over which olfactory experience-22Canonically, in these brain regions, the combinatorial nature of activity patterns that 48 encode different odors is conserved across animals and are species specific (Galizia et 49 al., 1999b). These olfactory codes result from binding of volatile chemicals to peripheral 50 olfactory receptor neurons (ORNs) that then project, via axon terminals, to glomeruli in 51 the OB in mammals or the AL in insects (Buck and Axel, 1991, Hildebrand and 52