Effects of Early Postnatal Alcohol Exposure on Learning in the Developing Rat: Replication With Intubation Method of Delivery

• Published in: Alcoholism, clinical and experimental research Vol. 23; no. 6; pp. 1085 - 1093
• Main Authors: Lilliquist, Michael W., Highfield, David A., Amsel, Abram
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-06-1999; Lippincott Williams & Wilkins
• Subjects: Alcoholism and acute alcohol poisoning; Animals; Animals, Newborn; Biological and medical sciences; Central Nervous System Depressants - administration & dosage; Central Nervous System Depressants - blood; Central Nervous System Depressants - pharmacology; Discrimination Learning; Esophagus; Ethanol - administration & dosage; Ethanol - blood; Ethanol - pharmacology; Extinction, Psychological; Fetal Alcohol Syndrome; Intubation; Learned Persistence; Learning - drug effects; Medical sciences; Motor Activity - drug effects; Postnatal Alcohol Exposure; Rats; Rats, Sprague-Dawley; Reward; Toxicology; Fetal alcohol syndrome; Ethanol; Rat; Toxicity; Memory; Rodentia; Cognition; Route of administration; Postnatal development; Learning; Vertebrata; Mammalia; Discrimination; Newborn animal; Behavior; Intubation
• ISSN: 0145-6008; 1530-0277
• DOI: 10.1111/j.1530-0277.1999.tb04229.x

Early postnatal exposure to alcohol during early development produces deficits in learned persistence, as reflected in the partial reinforcement extinction effect (PREE) in weanling rats, and deficits memory‐based learning, as shown by patterned single alternation (PSA) discrimination learning in preweanling rats. We report a partial replication of these effects using the intubation method instead of artificial rearing. Rat pups were intubated once per day with 4.5 g/kg/day alcohol in a milk‐based diet or control diet on postnatal days (PNDs) 4 to 9, and then assessed for the PREE on PNDs 20 and 21 or PSA learning on PNDs 17 and 18. Compared with previous artificial rearing reports, the intubation method produced healthier and heavier pups, and yielded a consistently lower and less variable blood alcohol levels. Even with the lower alcohol levels, intubation with alcohol eliminated the PREE. Intubation with alcohol had a weaker but still detrimental effect on PSA learning. These results suggest that alcohol exposure during development can produce behavioral deficits in the absence of the more severe effects on brain and body growth typically associated with fetal alcohol syndrome.