Department of Psychobiology, University of Granada, Granada 18071, Granada, Spain; Mind, Brain and Behavior Research Center (CIMCYC), University of Granada, Granada 18071, Spain.
Neurobiol Learn Mem. 2020 Sep;173:107264. doi: 10.1016/j.nlm.2020.107264. Epub 2020 Jun 3.
Rats are often reluctant to consume novel tastes because they lack knowledge about the postingestive effects the new foods might have. This paper examines the effect of excitotoxic lesions and temporary inactivation of the perirhinal cortex (Prh), a key region in the recognition memory system, on taste neophobia and its attenuation. Using a two-bottle choice paradigm (saccharin vs water), excitotoxic lesions were found to disrupt taste neophobia to 0.3% and 0.5% saccharin. However, the lesions had no effect when using a concentration of 0.7%, which is qualitatively aversive (expt. 1a-1c). In a second series of experiments the same animals were able to acquire a flavor preference learning on the basis of a flavor-taste association. Lesioned and control rats showed, during a choice test, a clear preference for the flavor associated with saccharin (expt. 2a-2c). Finally, in a third series of experiments, Prh inactivation with lidocaine after trial 1 (expt. 3) and after trials 1-3 (expt. 4) delayed attenuation of the neophobia. These findings suggest that Prh lesions do not significantly affect taste processing/ perception. Prh thus appears to play an essential role in taste neophobia and its attenuation.
老鼠通常不愿意食用新的口味，因为它们不知道新食物可能带来的味觉后效。本文研究了兴奋性毒性损伤和暂时性损毁边缘下皮层（Prh）对味觉恐惧形成及其衰减的影响。采用双瓶选择范式（糖精对比水），结果发现兴奋性毒性损伤破坏了对 0.3%和 0.5%糖精的味觉恐惧形成，但对 0.7%糖精（味觉上厌恶）的味觉恐惧形成没有影响（实验 1a-1c）。在一系列的第二项实验中，相同的动物能够基于味觉-味道的关联获得味道偏好学习。在选择测试中，损伤和对照组的老鼠对与糖精相关的味道表现出明显的偏好（实验 2a-2c）。最后，在第三系列实验中，在第一试验后（实验 3）和在第一至第三试验后（实验 4）用利多卡因对 Prh 进行失活，延迟了味觉恐惧的衰减。这些发现表明，Prh 损伤对味觉处理/感知没有显著影响。因此，Prh 似乎在味觉恐惧形成及其衰减中起着至关重要的作用。
