Hansen S
Department of Psychology, University of Göteborg, Sweden.
Physiol Behav. 1994 Apr;55(4):615-20. doi: 10.1016/0031-9384(94)90034-5.
The present experiments characterized the impairment in pup retrieval previously observed in maternal rats following dopamine-depleting 6-hydroxydopamine (6-OHDA) infusions in the ventral striatum. Video recordings of 30-min pup retrieval tests revealed that 6-OHDA mothers spent most of the time feeding (Experiment 1). Denying the mothers the opportunity to eat during testing failed to reestablish pup retrieval. Similarly unsuccessful was an attempt to evoke food-motivated pup retrieving in 6-OHDA mothers by coating the stimulus pups' skin with a 4% sucrose solution (Experiment 2). However, restoration of pup retrieval was observed in 6-OHDA mothers that had been separated from their pups for 3-6 h (Experiments 3 and 4). Stimulation of ultrasonic callings by clonidine treatment of the stimulus pups, or leaving pups in the nest during testing, were not significantly effective (Experiment 3). These data suggest that separation-induced increases in maternal motivation can override the inhibitory effect of ventral striatal dopamine depletion on pup retrieval.
本实验对先前观察到的母鼠在腹侧纹状体注射多巴胺耗竭剂6-羟基多巴胺（6-OHDA）后出现的幼崽找回障碍进行了特征描述。30分钟幼崽找回测试的视频记录显示，注射6-OHDA的母鼠大部分时间都在进食（实验1）。在测试期间不让母鼠进食并不能恢复幼崽找回行为。同样，试图通过用4%蔗糖溶液涂抹刺激幼崽的皮肤来唤起注射6-OHDA的母鼠的食物驱动型幼崽找回行为也未成功（实验2）。然而，在与幼崽分离3 - 6小时的注射6-OHDA的母鼠中观察到了幼崽找回行为的恢复（实验3和4）。用可乐定处理刺激幼崽以刺激超声波鸣叫，或在测试期间将幼崽留在巢中，效果均不显著（实验3）。这些数据表明，分离诱导的母性动机增加可以克服腹侧纹状体多巴胺耗竭对幼崽找回行为的抑制作用。
