Differential memory persistence of odor mixture and components in newborn rabbits: competition between the whole and its parts.
Front. Behav. Neurosci.. 2014-06-16; 8:
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1. Front Behav Neurosci. 2014 Jun 16;8:211. doi: 10.3389/fnbeh.2014.00211.
Differential memory persistence of odor mixture and components in newborn
rabbits: competition between the whole and its parts.
Coureaud G(1), Thomas-Danguin T(1), Datiche F(1), Wilson DA(2), Ferreira G(3).
(1)Centre des Sciences du Goût et de l’Alimentation (CSGA), UMR 6265 CNRS, UMR
1324 INRA, Université de Bourgogne Dijon, France.
(2)Department of Child and Adolescent Psychiatry, New York University Langone
School of Medicine New York, NY, USA.
(3)Nutrition and Integrative Neurobiology Group, INRA UMR 1286 Bordeaux, France ;
Université de Bordeaux Bordeaux, France.
Interacting with the mother during the daily nursing, newborn rabbits experience
her body odor cues. In particular, the mammary pheromone (MP) contained in rabbit
milk triggers the typical behavior which helps to localize and seize the nipples.
It also promotes the very rapid appetitive learning of simple or complex stimuli
(odorants or mixtures) through associative conditioning. We previously showed
that 24 h after MP-induced conditioning to odorants A (ethyl isobutyrate) or B
(ethyl maltol), newborn rabbits perceive the AB mixture in a weak configural way,
i.e., they perceive the odor of the AB configuration in addition to the odors of
the elements. Moreover, after conditioning to the mixture, elimination of the
memories of A and B does not affect the memory of AB, suggesting independent
elemental and configural memories of the mixture. Here, we evaluated whether
configural memory persistence differs from elemental one. First, whereas 1 or
3-day-old pups conditioned to A or B maintained their responsiveness to the
conditioned odorant for 4 days, those conditioned to AB did not respond to the
mixture after the same retention period. Second, the pups conditioned to AB still
responded to A and B 4 days after conditioning, which indicates stronger
retention of the elements than of the configuration when all information are
learned together. Third, we determined whether the memory of the elements
competes with the memory of the configuration: after conditioning to AB, when the
memories of A and B were erased using pharmacological treatment, the memory of
the mixture was extended to day 5. Thus, newborn rabbits have access to both
elemental and configural information in certain odor mixtures, and competition
between these distinct representations of the mixture influences the persistence
of their memories. Such effects certainly occur in the natural context of
mother-pup interactions and may contribute to early acquisition of knowledge
about the surroundings.