Molero-Chamizo Andrés
Department of Psychobiology, University of Granada, Spain ;
Acta Neurobiol Exp (Wars). 2018;78(3):242-250.
The role of the amygdala in the acquisition of conditioned taste aversion (CTA) is unclear. The lesion studies that have explored specific nuclei of the amygdala point to a probable involvement of the basolateral amygdala, but it remains unclear whether the function of the amygdala in CTA is limited to the activity of the basolateral amygdala. In the current study, extensive bilateral lesions of the amygdala were performed in Wistar rats to explore if the destruction of the amygdala affects the acquisition of CTA, as has been reported with selective lesions of the basolateral amygdala. The magnitude of the taste aversion of animals with extensive lesions of the amygdala was compared with those of animals with similar lesions of the striatum (a structure apparently unrelated to CTA) and animals without lesions. Taste aversion was analyzed by the one‑bottle test and two‑bottle choice test. The results of the one‑bottle test indicated that amygdaloid lesions significantly reduced the magnitude of taste aversion compared with that of animals without lesions. Animals with lesions of the amygdala also showed a greater preference for the conditioned taste stimulus, but this preference did not reach statistical significance. Besides the effect on CTA, animals with amygdaloid lesions showed no evidence of taste neophobia on the day of conditioning. These findings suggest that amygdaloid lesions may affect CTA by disrupting the perception of novelty during conditioning in a manner similar to the effect reported with basolateral lesions.
杏仁核在条件性味觉厌恶（CTA）形成过程中的作用尚不清楚。探索杏仁核特定核团的损伤研究表明基底外侧杏仁核可能参与其中，但杏仁核在CTA中的功能是否仅限于基底外侧杏仁核的活动仍不明确。在本研究中，对Wistar大鼠进行了广泛的双侧杏仁核损伤，以探究杏仁核的破坏是否会影响CTA的形成，正如基底外侧杏仁核选择性损伤的报道那样。将杏仁核广泛损伤的动物的味觉厌恶程度与纹状体有类似损伤的动物（一种明显与CTA无关的结构）以及未损伤的动物进行比较。通过单瓶试验和双瓶选择试验分析味觉厌恶。单瓶试验结果表明，与未损伤的动物相比，杏仁核损伤显著降低了味觉厌恶程度。杏仁核损伤的动物对条件性味觉刺激也表现出更大的偏好，但这种偏好未达到统计学意义。除了对CTA的影响外，杏仁核损伤的动物在条件化当天没有表现出味觉新恐惧症的迹象。这些发现表明，杏仁核损伤可能通过类似于基底外侧损伤所报道的方式，在条件化过程中破坏新奇感的感知，从而影响CTA。
