Heightened ethanol intake in infant and adolescent rats following nursing experiences with an ethanol-intoxicated dam. Alcoholism: Clinical & Experimental Research

M.Y., P.; PAULA ABATE; N.E., S.; J.C., M.

ALCOHOLISM: CLINICAL AND EXPERIMENTAL RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Año: 2004 vol. 28 p. 895 - 905

0145-6008

Background: Preweanling rats detect ethanol (175 mg/100 ml) in maternal milk when the dam ismoderately intoxicated. Repeated experiences with the intoxicated dam facilitate subsequent recognition ofethanol’s chemosensory attributes and promote ethanol-related memories with a negative hedonic content.This memory has been attributed to the infant’s acquired association between ethanol’s chemosensoryattributes and its disruptive effects on maternal care. In this study, infant and adolescent ethanol intakepatterns were analyzed as a function of prior interactions, during early infancy, with their intoxicated dams.Methods: During postpartum days 3, 5, 7, 9, 11, and 13, breast-feeding dams received an intragastricadministration of either 2.5 g/kg of ethanol or water. Pups whose dams had been given one of these twomaternal treatments were tested on postnatal day 15 for ingestion of 0% (water), 2.5, 5.0, or 10% v/v ethanolsolution. During adolescence, remaining animals from these litters were first adapted to ingest water fromdrinking tubes and then were given simultaneous access to tap water and a given ethanol solution. The firstday, a 3%v/v ethanol solution was used. This solution was increased by 1% ethanol each following day untilthe solution was 6% v/v ethanol.Results: Maternal drug treatment did not affect the body weights of dams, infants, or adolescents. Waterintake during infancy and adolescence also was unaffected by prior maternal treatment. However, infantsthat had previously interacted with ethanol-intoxicated dams exhibited heightened ethanol intake scores(grams per kilogram and percentage body weight gains), especially when tested with 5 or 10% v/v ethanolsolutions. Similarly, adolescent males (but not females) that had interacted with an intoxicated dam duringinfancy also had higher ethanol consumption levels than those that had interacted with a nonintoxicateddam.Conclusions: Contrary to what might be expected in animals that acquire an aversive memory forethanol’s chemosensory cues as a function of prior interactions with an intoxicated mother, these resultsindicate that such interactions promote a long-lasting increase in ethanol intake. These results suggest thatrats reared by intoxicated dams become sensitive to the negative reinforcing properties of ethanol.