Associative learning during early adulthood enhances later memory retention in honeybees.
BACKGROUND
Cognitive experiences during the early stages of life play an important role in shaping the future behavior in mammals but also in insects, in which precocious learning can directly modify behaviors later in life depending on both the timing and the rearing environment. However, whether olfactory associative learning acquired early in the adult stage of insects affect memorizing of new learning events has not been studied yet.


METHODS
Groups of adult honeybee workers that experienced an odor paired with a sucrose solution 5 to 8 days or 9 to 12 days after emergence were previously exposed to (i) a rewarded experience through the offering of scented food, or (ii) a non-rewarded experience with a pure volatile compound in the rearing environment.


RESULTS
Early rewarded experiences (either at 1-4 or 5-8 days of adult age) enhanced retention performance in 9-12-day-conditioned bees when they were tested at 17 days of age. The highest retention levels at this age, which could not be improved with prior rewarded experiences, were found for memories established at 5-8 days of adult age. Associative memories acquired at 9-12 days of age showed a weak effect on retention for some pure pre-exposed volatile compounds; whereas the sole exposure of an odor at any younger age did not promote long-term effects on learning performance.


CONCLUSIONS
The associative learning events that occurred a few days after adult emergence improved memorizing in middle-aged bees. In addition, both the timing and the nature of early sensory inputs interact to enhance retention of new learning events acquired later in life, an important matter in the social life of honeybees.
Arenas
Andrés
A
Grupo de Estudio de Insectos Sociales, IFIBYNE-CONICET, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, Buenos Aires, Argentina.
Fernández
Vanesa M
VM
Farina
Walter M
WM
D000375:Aging / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001245:Association Learning / Q000187:drug effects / Q000502:physiology*; D001516:Bees / Q000187:drug effects / Q000502:physiology*; D001522:Behavior, Animal / Q000187:drug effects; D002241:Carbohydrates / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects; D004777:Environment; D005247:Feeding Behavior / Q000187:drug effects; D008136:Longevity / Q000187:drug effects; D009812:Odorants; D055696:Olfactory Perception / Q000187:drug effects; D012153:Retention, Psychology / Q000187:drug effects / Q000502:physiology*; D012996:Solutions; D014835:Volatilization
D002241:Carbohydrates; D012996:Solutions