A new protocol for measuring spatial learning and memory in the honey bee Apis mellifera: effects of behavioural state and cGMP

Abstract

The honey bee Apis mellifera is a model organism for studying learning and memory in insects. Although much work has been done to study olfactory learning using the proboscis extension reflex paradigm, we currently lack a high throughput method to study spatial learning and memory under controlled conditions. Here we outline a new paradigm to study spatial learning and memory in honey bees based on a food search task adopted from the vertebrate literature. After establishing that honey bees are able to learn and recall the location of artificial flowers inside the testing arena, we used the procedure to compare the performance of young nurse bees, who stay in the colony and nurse the brood, and old forager bees who forage outside. We also compared the spatial learning and memory of age-staged bees that were experimentally treated with cyclic guanosine monophosphate (cGMP), which causes precocious foraging, and cyclic adenosine monophosphate (cAMP), which does not alter behavioural state. Although foragers and nurses from typical colonies had similar learning curves, we found that foragers were significantly more accurate when recalling the location of previously rewarding artificial flowers inside the testing arena. This effect was also observed when comparing age-staged bees that have been chronically exposed to cGMP vs. those chronically exposed to cAMP. The Food Search Box paradigm is a simple and effective way to study spatial learning and memory in honey bees.