Different roles for different modulators in the learning of worms

Multiple neuromodulators are involved in learning and memory. However, the differences and similarities in mechanisms underlying how each neuromodulator regulates behaviors in learning are not well understood. Recently, we found that dopamine and neuropeptide signalings are both required for odor learning of the nematode Caenorhabditis elegans. Interestingly, quantitative behavioral and genetic analyses have indicated that neuropeptide and dopamine signalings are independently required for the acquisition and execution of memory, respectively. In fact, dopamine signaling appears to be required to suppress deteriorating behavioral changes associated with learning. Such different roles of multiple neuromodulators in learning could be evolutionarily conserved.