Ramos Juan M J
Department of Psychobiology, Campus Cartuja, University of Granada, Granada 18071, Spain.
Behav Brain Res. 2015 May 1;284:94-102. doi: 10.1016/j.bbr.2015.02.017. Epub 2015 Feb 16.
Although the perirhinal cortex (Prh) has been extensively related to recognition memory, little is known about its specific role in taste memories. The main aim of the present series was therefore to examine the effect of neurotoxic lesions of the Prh on taste neophobia, a phenomenon consisting of a low intake of a novel food until its postingestive consequences are determined. The results showed that Prh-lesioned rats consumed significantly more novel saccharin in trial 1 than control subjects when a saccharin solution of 0.3% (expt. 1a) and 0.5% (expt. 1b) was presented. However, when the saccharin concentration was high and qualitatively more aversive, Prh lesions did not affect the neophobic response (0.7%, expt. 1c) and the lesioned and control animals consumed a similar amount of the fluid during the first and subsequent test trials. In all three experiments, Prh-lesioned and control rats showed a comparable intake at asymptote. Experiment 2 and 3 showed that neurotoxic lesions to the dorsal hippocampus prior to or 24h after the intake of the novel taste (0.3% saccharin) had no effect on the initial occurrence of the neophobic response or on the consolidation of safe taste memory, respectively. These findings support a dissociation of functions between the Prh and the hippocampus in taste neophobia. Also, the data suggests that the Prh plays an essential role in detecting the novelty of the new tastant.
尽管嗅周皮质（Prh）与识别记忆密切相关，但对于其在味觉记忆中的具体作用却知之甚少。因此，本系列研究的主要目的是检验Prh的神经毒性损伤对味觉新异恐惧症的影响，味觉新异恐惧症是一种在确定新食物摄入后结果之前对其摄入量较低的现象。结果显示，当呈现0.3%（实验1a）和0.5%（实验1b）的糖精溶液时，在实验1中，Prh损伤的大鼠在第1次试验中摄入的新型糖精显著多于对照动物。然而，当糖精浓度较高且在性质上更具厌恶性时，Prh损伤并未影响新异恐惧反应（0.7%，实验1c），并且在首次及随后的测试试验中，损伤组和对照组动物摄入的液体量相似。在所有三个实验中，Prh损伤的大鼠和对照大鼠在渐近线时的摄入量相当。实验2和3表明，在摄入新型味觉物质（0.3%糖精）之前或之后24小时对背侧海马体进行神经毒性损伤，分别对新异恐惧反应的初始出现或安全味觉记忆的巩固没有影响。这些发现支持了在味觉新异恐惧症中Prh和海马体之间功能的分离。此外，数据表明Prh在检测新味觉剂的新颖性方面起着至关重要的作用。
