Prenatal exposure to ethanol during late gestation facilitates operant self-administration of the drug in 5-day-old rats

• Autores: Miranda Morales, Roberto Sebastián; Nizhnikov, Michael; Spear, Norman E.
• Año de publicación: 2014
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Prenatal Ethanol Exposure; Late Gestation; Ethanol Reinforcement; Operant Self-Administration; Infant Rat
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Prenatal ethanol exposure modifies postnatal affinity to the drug, increasing the probability of ethanol use and abuse. The present study tested developing rats (5-day-old) in a novel operant technique to assess the degree of ethanol self-administration as a result of prenatal exposure to low ethanol doses during late gestation. On a single occasion during each of gestational days 17–20, pregnant rats were intragastrically administered ethanol 1 g/kg, or water (vehicle). On postnatal day 5, pups were tested on a novel operant conditioning procedure in which they learned to touch a sensor to obtain 0.1% saccharin, 3% ethanol, or 5% ethanol. Immediately after a 15-min training session, a 6-min extinction session was given in which operant behavior had no consequence. Pups were positioned on a smooth surface and had access to a touch-sensitive sensor. Physical contact with the sensor activated an infusion pump, which served to deliver an intraoral solution as reinforcement (Paired group). A Yoked control animal evaluated at the same time received the reinforcer when its corresponding Paired pup touched the sensor. Operant behavior to gain access to 3% ethanol was facilitated by prenatal exposure to ethanol during late gestation. In contrast, operant learning reflecting ethanol reinforcement did not occur in control animals prenatally exposed to water only. Similarly, saccharin reinforcement was not affected by prenatal ethanol exposure. These results suggest that in 5-day-old rats, prenatal exposure to a low ethanol dose facilitates operant learning reinforced by intraoral administration of a low-concentration ethanol solution. This emphasizes the importance of intrauterine experiences with ethanol in later susceptibility to drug reinforcement. The present operant conditioning technique represents an alternative tool to assess self-administration and seeking behavior during early stages of development.
Fil: Miranda Morales, Roberto Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina
Fil: Nizhnikov, Michael. University Of Binghamton; Estados Unidos
Fil: Spear, Norman E.. University Of Binghamton; Estados Unidos