"we used reporter transgenic worms in which GFP expression is controlled by the CRE reporter (pCRE::GFP) (Kimura et al., 2002). In untrained worms, CREB activity is barely detectible (Figure 4A). After spaced butanone/food long-term memory training, we observed fluorescence in two sets of neurons (Figures 4A and 4B); this fluorescence increase is abrogated in a
crh-1 mutant (Figure 4C)."