Maternal Odor Exposure Modulates Acceptance of a Bitter Taste in Newborn and Infant Rats

IFRÁN, MARÍA C.; SUÁREZ, ANDREA B.; PAUTASSI, RICARDO M.; KAMENETZKY, GISELLE V.

Frontiers in Psychology

Frontiers Media SA

Lugar: Lausanne; Año: 2018 vol. 9

The acceptance of bitter, aversive, substances during early life is enhanced bystimulation with familiar, pre-exposed odors. Newborn rats exhibited heightened graspresponses toward an artificial nipple dispensing quinine, and drank more of this bittersolution, if concurrently stimulated with a lemon odor they had been exposed to shortlyafter birth. It yet unknown, however, if odors made familiar via normative developmentalmilestones also acquire modulatory influence upon seeking and intake of basic tastants.The current study assessed the influence of exposure to maternal odor on intake andgrasp responses toward a surrogate nipple providing quinine, in 3-day (Experiment 1) or12-day (Experiment 2) old, Wistar rat pups. The results revealed enhanced seeking andintake of the bitter solution, but not of water, in animals tested in the presence of themother (and hence exposed to its odor cues), at both ages, compared to counterpartsgiven either no explicit odor stimulation or stimulation to the odor of an unrelated dam.These results, obtained with a biologically relevant odor, are consistent with thosepreviously found with a neutral, arbitrary odor. It seems that during the early stagesof development, familiar odors regulate the acceptance of non-palatable, otherwiserejected, flavors.