Consumption of an acute dose of caffeine reduces acquisition but not memory in the honey bee.

Caffeine affects several molecules that are also involved in the processes underlying learning and memory such as cAMP and calcium. However, studies of caffeine's influence on learning and memory in mammals are often contradictory. Invertebrate model systems have provided valuable insight into the actions of many neuroactive compounds including ethanol and cocaine. We use the honey bee (Apis mellifera) to investigate how the ingestion of acute doses of caffeine before, during, and after conditioning influences performance in an appetitive olfactory learning and memory task. Consumption of caffeine doses of 0.01 M or greater during or prior to conditioning causes a significant reduction in response levels during acquisition. Although bees find the taste of caffeine to be aversive at high concentrations, the bitter taste does not explain the reduction in acquisition observed for bees fed caffeine before conditioning. While high doses of caffeine reduced performance during acquisition, the response levels of bees given caffeine were the same as those of the sucrose only control group in a recall test 24h after conditioning. In addition, caffeine administered after conditioning had no affect on recall. These results suggest that caffeine specifically affects performance during acquisition and not the processes involved in the formation of early long term memory.