From antenna to antenna: Lateral shift of olfactory memory in bees

Abstract

Honeybees, _Apis mellifera_, readily learn to associate odours with sugar rewards and we show here that recall of the olfactory memory, as demonstrated by the bee extending its proboscis when presented with the trained odour, involves first the right and then the left antenna. At 1-2 hour after training using both antennae, recall is possible only when the bee uses its right antenna but by 6 hours after training the memory has made a lateral shift and can now be recalled only when the left antenna is in use. Long-term memory one day after training is also accessed only via the left antenna. This time-dependent shift from right to left antenna is seen as side biases in responding to odour presented to the bee's left or right side and hence may be manifested in natural behaviour.