How honey bees learn to ignore irrelevant stimuli: Are learning and foraging genotypes part of the same behavioral syndrome

The primary focus of this thesis was to examine the correlation between the heightened expression of learning behavior and pollen foraging in honey bees. The first objective was to develop a visual based proboscis extension reflex (PER) assay to evaluate subjects using both a visual and more traditional olfactory learning assay. The availability of two stimulus modalities facilitated the examination of intermodal stimulus interaction. Restrained intact honey bees can be successfully conditioned to discriminate diffuse blue and green light stimuli with recall present after 24 hours. However, subjects did not exhibit intermodal stimulus interaction under these experimental conditions. The second focus area utilized the visual learning paradigm to examine two genetic lines of honey bees, one selected for high and low levels of conditioned stimulus preexposure effect (CSPE) learning and the other for high and low levels of pollen collecting behavior. Earlier work using only the CSPE lines suggested a correlation between the expression of CSPE and the tendency to forage for pollen. Tests showed that while both the pollen and CSPS lines exhibited visual discrimination teaming, there were differences between the sublines in their response to the unreinforced light stimulus. This behavioral comparison revealed that if there is a common genetic basis that it is at least multigenic and only a partial overlap in the expression of learning behavior. The third chapter attempted to explore a potential underlying mechanism for the expression of CSPE learning. The third chapter examined the effect of nitric oxide (NO), a potential regulator in the neurological pathway for the expression of CSPE. Nitric oxide is a broadly functioning neurotransmitter, present in the olfactory learning pathway of honey bees. Reduced NO levels did not attenuate the expression of CSPE. Therefore, it was concluded that NO was not involved in the CSPE pathway. A genetic analysis of subjects provided the last piece of insight into the structural underpinnings of CSPE. The use of single nucleotide polymorphism (SNP) technology was an effort to test the common basis between the two lines in greater detail. Mapping results revealed a significant QTL shared by the pollen and CSPE lines.