title: Prenatal ethanol increases sucrose reinforcement, an effect strengthened by postnatal association of ethanol and sucrose.
abstract: Late prenatal exposure to ethanol recruits sensory processing of the drug and of its motivational properties, an experience that leads to heightened ethanol affinity. Recent studies indicate common sensory and neurobiological substrates between this drug and sweet tastants. Using a recently developed operant conditioning technique for infant rats, we examined the effects of prenatal ethanol history upon sucrose self-administration (postnatal days, PDs 14-17). Prior to the last conditioning session, a low (0.5 g/kg) or a high (2.5 g/kg) ethanol dose were paired with sucrose. The intention was to determine if ethanol would inflate or devalue the reinforcing capability of the tastant and if these effects are dependent upon prenatal ethanol history. Male and female pups prenatally exposed to ethanol (2.0 g/kg) responded more when reinforced with sucrose than pups lacking this antenatal experience. Independently of prenatal status, a low ethanol dose (0.5 g/kg) enhanced the reinforcing capability of sucrose while the highest dose (2.5 g/kg) seemed to ameliorate the motivational properties of the tastant. During extinction (PD 18), two factors were critical in determining persistence of responding despite reinforcement omission. Pups prenatally exposed to ethanol that subsequently experienced the low ethanol dose paired with sucrose, showed higher resistance to extinction. The effects here reported were not associated with differential blood alcohol levels across prenatal treatments. These results indicate that fetal ethanol experience promotes affinity for a natural sweet reinforcer and that low doses of ethanol are also capable of enhancing the positive motivational consequences of sucrose when ethanol and sucrose are paired during infancy.
authors.affiliation: Instituto de Investigación Médica M. y M. Ferreyra (INIMEC - CONICET), Friuli 2434, C.P. 5016 Córdoba, Argentina. Electronic address: mcullere@immf.uncor.edu.
authors.forename: Marcela Elena
authors.initials: ME
authors.lastname: Culleré
authors.affiliation: Center for Developmental Psychobiology, Binghamton University, Binghamton, NY 13902-6000, USA.
authors.forename: Norman E
authors.initials: NE
authors.lastname: Spear
authors.affiliation: Instituto de Investigación Médica M. y M. Ferreyra (INIMEC - CONICET), Friuli 2434, C.P. 5016 Córdoba, Argentina; Center for Developmental Psychobiology, Binghamton University, Binghamton, NY 13902-6000, USA; Facultad de Psicología, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Molina
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects; D000431:Ethanol / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D005260:Female; D005333:Fetus / Q000187:drug effects*; D008297:Male; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012054:Reinforcement, Psychology; D012646:Self Administration; D013395:Sucrose / Q000008:administration & dosage
chemical_list: D000431:Ethanol; D013395:Sucrose
keywords: Ethanol; Fetus; Infant; Operant conditioning; Second order conditioning; Sucrose