Ethanol-Mediated fetal learning modulates neonatal responsiveness to an ethanol scented artificial nipple

PUETA, M.; ABATE, P.; SPEAR, N.E.; MOLINA, J.C.

Vancouver, Canadá.

Congreso; 27th Scientific Meeting of the Research Society on Alcoholism; 2004

Research Society on Alcoholism

ETHANOL-MEDIATED FETAL LEARNING MODULATES NEONATAL RESPONSIVENESS TO AN ETHANOL SCENTED ARTIFICIAL NIPPLE. P Abate, M Pueta, NE Spear & JC Molina. Inst. Ferreyra, Fac. Psicología UNC, Argentina & Center Dev. Psychobiology, Binghamton University, USA. Near-term fetuses acquire an associative memory supported by ethanol’s unconditioned effects. This learning is established after four conditioning trials where chemosensory cues (cineole) present in the amniotic fluid are paired with maternal-fetal ethanol intoxication. Neonates are prone to vigorously attach to a surrogate nutritive nipple scented with odors that were prenatally associated with the drug. Two experiments were conducted to analyze if ethanol-mediated prenatal learning can be established with only two conditioning trials and when utilizing a relatively low ethanol dose (1 g/kg). In both experiments prenatal treatments were conducted during gestational days (GDs) 19 and 20 and were defined as follows: Paired group, dams received an i.g. administration of cineole followed 15 min. later by a 1.0 g/kg EtOH dose; Long-delay group, dams received cineole 4 hours before ethanol intoxication; Water group, dams received two administrations of water separated by 15 min. In Experiment 1 and following cesarean delivery (GD 21), pups were evaluated in terms of their responsiveness to a surrogate nipple that provided milk. The nipples were either scented with cineole or ethanol or were unscented. In Experiment 2, neonates were stimulated with either a cineole scented or an unscented artificial nipple, both delivering a 6% v/v ethanol solution. Time of attachment, mean grasp duration and latency to attach for the 1rst time were considered as dependent variables. In Experiment 1 Paired pups were observed to exhibit heightened responsiveness to the nipple whenever this device was scented with ethanol odor. Similarly, in Experiment 2 the ANOVA revealed that Paired pups spent significantly more time attached to the nipples that delivered ethanol when compared with the remaining prenatal treatments. These results confirm previous findings that fetuses process ethanol chemosensory cues following maternal administration of the drug. Under the present experimental conditions ethanol-related memories were expressed only when cineole was administered in close temporal contiguity with ethanol. It is possible that with few conditioning trials, fetal experience with cineole facilitates subsequent processing of ethanol in the amniotic fluid and/or learning about the contingency between ethanol chemosensory cues present in this biological fluid and pharmacological effects of the drug.