Boyer Brigitte, Ernest Sylvain, Rosa Frédéric
INSERM U 1024, CNRS UMR 8197, Ecole Normale Supérieure, IBENS, Developmental Biology Paris, France.
Front Behav Neurosci. 2013 May 22;7:51. doi: 10.3389/fnbeh.2013.00051. eCollection 2013.
As soon as zebrafish larvae start eating, they exhibit a marked aversion for bitter and acidic substances, as revealed by a consumption assay, in which fluorescent Tetrahymena serve as a feeding basis, to which various stimuli can be added. Bitter and acidic substances elicited an increase in mRNA accumulation of the immediate-early response gene egr-1, as revealed by in situ hybridization. Conversely, chemostimulants that did not induce aversion did not induce egr-1 response. Maximum labeling was observed in cells located in the oropharyngeal cavity and on the gill rakers. Gustatory areas of the brain were also labeled. Interestingly, when bitter tastants were repeatedly associated with food reward, zebrafish juveniles learned to ingest food in the presence of the bitter compound. After habituation, the acquisition of acceptance for bitterness was accompanied by a loss of egr-1 labeling. Altogether, our data indicate that egr-1 participates specifically in food aversion. The existence of reward-coupled changes in taste sensitivity in humans suggests that our results are relevant to situations in humans.
斑马鱼幼体一开始进食，就会对苦味和酸性物质表现出明显的厌恶，这是通过一项摄食试验揭示的，在该试验中，荧光四膜虫作为进食基础，可添加各种刺激物。原位杂交显示，苦味和酸性物质会引发即刻早期反应基因egr-1的mRNA积累增加。相反，未诱导厌恶的化学刺激物不会诱导egr-1反应。在位于口咽腔和鳃耙上的细胞中观察到最大标记。大脑的味觉区域也有标记。有趣的是，当苦味剂与食物奖励反复关联时，斑马鱼幼鱼学会在苦味化合物存在的情况下摄取食物。习惯化后，对苦味接受度的获得伴随着egr-1标记的丧失。总之，我们的数据表明egr-1特别参与食物厌恶。人类味觉敏感性存在奖励耦合变化，这表明我们的结果与人类情况相关。
