Could pre-imaginal olfactory experiences modify the post-metamorphic odor-mediated responses in a social insect?

RAMIREZ GABRIELA P.; ARENAS ANDRES; FARINA WALTER M.

Huerta Grande

Congreso; 2nd Latin American Meeting of Chemical Ecology; 2012

In honeybee colonies the information of exploited resources is transferred among nest mates through mouth-to-mouth trophallaxis events. These social interactions also involve larvae as food recipients. We wonder if appetitive olfactory experiences that occur during pre-imaginal stages influence post-metamorphic odor-mediated responses. To address the issue we tested learning performance and memory retention in adults of 3/5 days old that underwent a pre-imaginal experience. Such experience was done by means of a scented-sucrose solution offered inside the hive and tested under the proboscis extension response (PER) paradigm in the lab. Results showed that precocious experience increased the PER-levels toward the pre-exposed odor suggesting retention of information gained prior to the emergence. Interestingly, high PER-levels to novel odors were also found accordingly to perceptual similarities between pre-exposed and different novel odors, resembling generalization in tested adults. Lastly, we found that even those bees that did not respond to the pre-exposed odor improved their learning performance in a PER-conditioning. Moreover these olfactory experiences could have influence at the peripheral level therefore the activity of the olfactory receptor neurons was analyzed by means of electroantennogram records (EAG). Also the number of olfactory sense organ (e.g. sensilla placoidea) was measured. These analyses led to electrophysiology and structural modifications that could be explained by a differential development of bees due to a pre-imaginal olfactory experience. This kind of pre-imaginal experiences may allow bees to assess food information very early in life with consequences in their odor-mediated responses like the learning ability during adult stage.