Pepino Marta Yanina, Abate Paula, Spear Norman E, Molina Juan Carlos
Instituto de Investigacion Medica Mercedes y Martin Ferreyra, INIMEC-Consejo Nacional de Investigaciones Cientificas y Tecnicas (MYP, PA, JCM), Cordoba, Argentina.
Alcohol Clin Exp Res. 2004 Jun;28(6):895-905. doi: 10.1097/01.alc.0000128223.95184.c9.
Preweanling rats detect ethanol (175 mg/100 ml) in maternal milk when the dam is moderately intoxicated. Repeated experiences with the intoxicated dam facilitate subsequent recognition of ethanol'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 chemosensory attributes and its disruptive effects on maternal care. In this study, infant and adolescent ethanol intake patterns were analyzed as a function of prior interactions, during early infancy, with their intoxicated dams.
During postpartum days 3, 5, 7, 9, 11, and 13, breast-feeding dams received an intragastric administration of either 2.5 g/kg of ethanol or water. Pups whose dams had been given one of these two maternal treatments were tested on postnatal day 15 for ingestion of 0% (water), 2.5, 5.0, or 10% v/v ethanol solution. During adolescence, remaining animals from these litters were first adapted to ingest water from drinking tubes and then were given simultaneous access to tap water and a given ethanol solution. The first day, a 3% v/v ethanol solution was used. This solution was increased by 1% ethanol each following day until the solution was 6% v/v ethanol.
Maternal drug treatment did not affect the body weights of dams, infants, or adolescents. Water intake during infancy and adolescence also was unaffected by prior maternal treatment. However, infants that 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 ethanol solutions. Similarly, adolescent males (but not females) that had interacted with an intoxicated dam during infancy also had higher ethanol consumption levels than those that had interacted with a nonintoxicated dam.
Contrary to what might be expected in animals that acquire an aversive memory for ethanol's chemosensory cues as a function of prior interactions with an intoxicated mother, these results indicate that such interactions promote a long-lasting increase in ethanol intake. These results suggest that rats reared by intoxicated dams become sensitive to the negative reinforcing properties of ethanol.
当母鼠处于中度醉酒状态时，断奶前的大鼠能够在母乳中检测到乙醇（175毫克/100毫升）。与醉酒母鼠的反复接触有助于后续识别乙醇的化学感官特性，并促进带有负面享乐内容的与乙醇相关的记忆。这种记忆被归因于婴儿在乙醇的化学感官特性与其对母性照料的干扰作用之间建立的习得性关联。在本研究中，分析了婴儿期和青春期的乙醇摄入模式，作为早期婴儿期与醉酒母鼠先前相互作用的函数。
在产后第3、5、7、9、11和13天，哺乳母鼠接受2.5克/千克乙醇或水的胃内给药。在出生后第15天，对其母鼠接受这两种母性处理之一的幼崽进行测试，以检测它们对0%（水）、2.5%、5.0%或10%（体积/体积）乙醇溶液的摄取情况。在青春期，这些窝中剩余的动物首先适应从饮水管摄取水，然后同时给予自来水和给定的乙醇溶液。第一天使用3%（体积/体积）的乙醇溶液。此后每天乙醇溶液的乙醇含量增加1%，直到溶液为6%（体积/体积）的乙醇。
母鼠的药物处理对母鼠、婴儿或青少年的体重没有影响。婴儿期和青春期的水摄入量也不受先前母性处理的影响。然而，先前与醉酒母鼠接触过的婴儿表现出更高的乙醇摄入分数（克/千克和体重增加百分比），尤其是在用5%或10%（体积/体积）乙醇溶液测试时。同样，在婴儿期与醉酒母鼠接触过的青春期雄性（而非雌性）的乙醇消费水平也高于与未醉酒母鼠接触过的雄性。
与根据动物因先前与醉酒母亲的相互作用而对乙醇的化学感官线索形成厌恶记忆所预期的情况相反，这些结果表明，这种相互作用会促进乙醇摄入量的长期增加。这些结果表明，由醉酒母鼠抚养长大的大鼠对乙醇的负面强化特性变得敏感。
