RELATIONSHIP BETWEEN PKG ACTIVITY, FORAGING AND MEMORY

n order to better understand the role of the foraging gene in the interactions between olfactory learning and memory, and foraging behaviours in Drosophila. melanogaster, we are undertaking two separate but related projects. In the first project, we are examining the effects of for on learning and memory in adult D. melanogaster to assess whether rovers and sitters respond differently to environmental heterogeneity as would be expected if the variants utilize different foraging strategies. Pavlovian interference paradigms (Bouton 1993) such as discrimination reversal learning, proactive interference and retroactive interference are being used to assess the flies’ abilities to respond to environmental heterogeneity in the context of learning. Because the pleiotropic effects of variation in for are well-known, specific hypotheses and predictions regarding the genetic variants can be made and tested using these paradigms.
A second project asks whether for plays a role in modulating the effects of environmental conditions on learning and memory in adult D. melanogaster. Since many phenotypes influenced by for have been shown to exhibit plastic responses to environmental variation, it stands to reason that the differential learning abilities of rovers and sitters previously described (Mery et al. 2007) may also be modified by environmental changes. Given that genetic variation in for is involved in many food-related and foraging phenotypes, we are examining the effect of food deprivation on learning ability in rovers and sitters. Specifically, we ask whether food deprivation alters the short-term memory (STM) differences known to exist between rovers and sitters. Depending on the results of these experiments, the effects of other stresses that have been shown to modulate for gene expression or phenotypes, such as heat stress (Dawson-Scully et al. 2007), may also be assessed for their influence on learning and memory.