Differential motimational properties of a high ethanol dose as a function of early postnatal development.

ARIAS, C; SANDERS, S; CHOTRO, M.G; MOLINA, J.C.; SPEAR, N.E.

Baltimore

Congreso; 29th Annual Scientific Meeting of the Research Society on Alcoholism (RSA)..; 2006

Research Society on Alcoholism (RSA)..

A recent study indicates that 3 g/kg ethanol during the end of the first postnatal week in the rat promotes subsequent heightened ethanol intake. A few days later this same dose decreases later ethanol intake. Rats process ethanol sensory cues derived from non metabolic elimination of the drug. Hence, these effects appear to reveal different associative learning processes across ontogeny mediated by the association between ethanol?s sensory and unconditioned properties. The mentioned paradoxical effects are congruent with the hypothesis of an early sensitive period where moderately aversive stimuli exert appetitive effects (Sullivan et al., 2000). In this study we examined motivational properties of ethanol during early ontogeny utilizing a Pavlovian conditioning procedure where ethanol intoxication (3 g/kg, intragastric administration) and saccharin intraoral infusions served as unconditioned (US) and conditioned stimulus (CS), respectively. Pups experienced paired presentations of these stimuli at 7-8 or 10-11 days of age (P groups). Control groups received unpaired presentations of the CS and US (UP) or the CS or US alone. Saccharin consumption tests were conducted at 24 and 48 hrs following conditioning trials. Younger animals assigned to the paired treatment were found to ingest significantly more saccharin than age-related control groups. Pups conditioned at 10-11 days of age showed significant reductions in saccharin intake scores when compared with appropriate controls. Peak blood ethanol levels were also determined in both age groups. No significant age differences were encountered. These results confirm and extend prior observations relative to an ontogenetic change in ethanol?s motivational properties. In conjunction with prior research it appears that ethanol during late gestation and early infancy exerts primarily appetitive effects. The motivational property of relatively high ethanol doses appears to dramatically change during commencement of the second postnatal week of life.