Association between events in time and space is a major mechanism for all animals, including humans, which allows them to learn about the world and potentially change their behavior in the future to adapt to different environments. Conditioning taste aversion (CTA) is a single-trial learning paradigm where animals are trained to avoid a novel flavor which is associated with malaise. Many variables can be analyzed with this model and the circuits involved are well described. Thus, the amygdala and the gustatory cortex (GC) are some of the most relevant structures involved in CTA. In the present study we focused in plastic changes that occur during appetitive and/or aversive taste memory formation. Previous studies have demonstrated that memory consolidation, in hippocampal dependent paradigms, induces plastic changes like increase in the concentration of proteins considered as markers of neuronal plasticity, such as the growth associated protein 43 (GAP-43) and synaptophysin (SYN). In the present experiment in male rats we evaluated changes in GAP-43 and SYN expression, using immunofluorescence, induce by the formation of aversive and appetitive taste memory. We found that taste aversive memory formation can induce an increase in GAP-43 in the granular layer of the GC. Furthermore, we also found an increase in SYN expression in both layers of the GC, the basolateral amygdala (BLA) and the central amygdala (CeA). These results suggest that aversive memory representation induces a new circuitry (inferred from an increase in GAP 43). On the other hand, an appetitive taste learning increased SYN expression in the GC (both layers), the BLA and the CeA without any changes in GAP 43. Together these results indicate that aversive memory formation induces structural and synaptic changes, while appetitive memory formation induces synaptic changes; suggesting that aversive and appetitive memories require a different set of cortical and amygdala plastic changes.

时间和空间中的事件之间的关联是包括人类在内的所有动物的主要机制，这使它们能够了解世界并可能在未来改变其行为以适应不同的环境。调节味觉厌恶 (CTA) 是一种单次试验学习范式，其中训练动物以避免与不适相关的新口味。可以使用该模型分析许多变量，并且很好地描述了所涉及的电路。因此，杏仁核和味觉皮层 (GC) 是参与 CTA 的一些最相关的结构。在本研究中，我们专注于在食欲和/或厌恶味觉记忆形成过程中发生的塑料变化。先前的研究表明，海马依赖范式中的记忆巩固，诱导可塑性变化，例如增加被视为神经元可塑性标志物的蛋白质浓度，例如生长相关蛋白 43 (GAP-43) 和突触素 (SYN)。在雄性大鼠的本实验中，我们评估了 GAP-43 和 SYN 表达的变化，使用免疫荧光，由厌恶和食欲味觉记忆的形成诱导。我们发现味觉厌恶记忆的形成可以诱导 GC 颗粒层中 GAP-43 的增加。此外，我们还发现 GC 两层、基底外侧杏仁核 (BLA) 和中央杏仁核 (CeA) 中 SYN 表达的增加。这些结果表明，厌恶的记忆表征诱导了一个新的电路（从 GAP 43 的增加推断出来）。另一方面，食欲学习增加了 GC（两层）中的 SYN 表达，BLA 和 CeA 在 GAP 中没有任何变化。表明厌恶和食欲的记忆需要一组不同的皮质和杏仁核可塑性变化。