CONICET | Buscador de Institutos y Recursos Humanos

Near-term rat fetuses detect sensory and toxic ethanol properties when the drug contaminates the prenatal milieu. Fetal conditioning involving a salient chemosensory cue (cineole) and EtOHs postabsorptive effects facilitates subsequent reinforcing effects of milk when this nutritional agent is contaminated with cineole. In the present study we analyzed neonatal operant conditioning patterns when using the following reinforcers: milk, ethanol (3 or 6% v/v solutions), a sucrose-quinine compound which mimics psychophysical attributes of ethanol or water. Pups in this study were derived from dams which during late gestation (GDs 1720) received daily i.g. administrations of water, 1.0 or 2.0 g/kg ethanol. On postnatal day 1 neonates were trained in an operant task. Paired pups received an intraoral administration of a given reinforcer (FR-1 schedule) when establishing physical contact with a touch sensitive sensor. Yoked controls were reinforced only when Paired pups activated the circuit. Paired pups exhibited heightened responsiveness during training when compared with Yoked controls. This difference did not achieve signifi cance when employing 6% v/v ethanol as a reinforcer. Interestingly, Paired pups prenatally exposed to 2.0 g/kg ethanol were observed to be particularly sensitive to the reinforcing effects of the sucrose-quinine compound and the 3% v/v ethanol solution. Paired pups born to dams treated with 1.0 g/kg ethanol were also found to be more sensitive to the reinforcing effects of 3% v/v ethanol when compared with counterparts prenatally exposed to water. Blood ethanol concentrations confi rmed that pups prenatally exposed to the drug self-administered higher amounts of the 3% v/v ethanol reinforcer when compared with pups prenatally exposed to water. These results indicate that late fetal experiences with ethanol facilitate the reinforcing effects of the drug and of a tastant that partially mimics its chemosensory properties.