Moles A, Valsecchi P, Cooper S J
Dipartimento di Biologia e Fisiologia, Generali Università degli Studi di Parma, V. le delle Scienze, 43100 Parma, Italy.
Department of Psychology, University of Durham, Durham DH1 3LE, UK.
Behav Processes. 1999 Mar 1;44(3):277-85. doi: 10.1016/s0376-6357(98)00031-x.
The present experiments were conducted to investigate the possible role of endogenous opioid peptides in the social transmission of food preferences in female mice. In the first experiment, observer animals were injected with 0.5 mg kg(-1) naltrexone, a long-lasting opioid receptor antagonist, 30 min prior to a 15-min period of social interaction with a familiar conspecific (demonstrator) fed either with a cocoa-flavoured or a plain diet. Afterwards, observers underwent a 30-min two-choice test between the cocoa and a more palatable, unfamiliar cinnamon diet. The results showed that opioid receptor blockade decreased the amount of cocoa diet consumed by the animals whose demonstrators ate cocoa diet. Experiment 2 showed that naltrexone, administered after the social interaction, strongly attenuated the expression of both a socially acquired preference for the cocoa diet and the spontaneous preference for the cinnamon diet. A third experiment was then conducted using the shorter-lasting opioid antagonist naloxone. Naloxone (0.5 mg kg(-1)) administered prior to the social interaction did not impair the acquisition of the food preference. Hence, results indicate that a blockade of opioid activity is sufficient to impair the expression of a socially acquired food preference but not its acquisition.
本实验旨在研究内源性阿片肽在雌性小鼠食物偏好的社会传递中可能发挥的作用。在第一个实验中，在观察动物与熟悉的同种个体（示范者）进行15分钟的社交互动前30分钟，给观察动物注射0.5 mg kg(-1)的纳曲酮（一种长效阿片受体拮抗剂），该示范者被喂食可可味或普通饮食。之后，观察动物在可可味食物和更美味的、不熟悉的肉桂味食物之间进行30分钟的二选一测试。结果表明，阿片受体阻断减少了其示范者食用可可味食物的动物所消耗的可可味食物量。实验2表明，在社交互动后给予纳曲酮，强烈减弱了对可可味食物的社会习得偏好和对肉桂味食物的自发偏好的表达。然后进行了第三个实验，使用作用时间较短的阿片拮抗剂纳洛酮。在社交互动前给予纳洛酮（0.5 mg kg(-1)）并不损害食物偏好的习得。因此，结果表明，阿片活性的阻断足以损害社会习得的食物偏好的表达，但不影响其习得。
