Gil-Lievana Elvi, Ramírez-Mejía Gerardo, Urrego-Morales Oscar, Luis-Islas Jorge, Gutierrez Ranier, Bermúdez-Rattoni Federico
Instituto de Fisiología Celular, División de Neurociencias, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Laboratory of Neurobiology of Appetitive, Department of Pharmacology, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV, Mexico City, Mexico.
Front Cell Neurosci. 2022 Mar 11;16:823220. doi: 10.3389/fncel.2022.823220. eCollection 2022.
Taste memory involves storing information through plasticity changes in the neural network of taste, including the insular cortex (IC) and ventral tegmental area (VTA), a critical provider of dopamine. Although a VTA-IC dopaminergic pathway has been demonstrated, its role to consolidate taste recognition memory remains poorly understood. We found that photostimulation of dopaminergic neurons in the VTA or VTA-IC dopaminergic terminals of TH-Cre mice improves the salience to consolidate a subthreshold novel taste stimulus regardless of its hedonic value, without altering their taste palatability. Importantly, the inhibition of the D1-like receptor into the IC impairs the salience to facilitate consolidation of an aversive taste recognition memory. Finally, our results showed that VTA photostimulation improves the salience to consolidate a conditioned taste aversion memory through the D1-like receptor into the IC. It is concluded that the dopamine activity from the VTA into IC is required to increase the salience enabling the consolidation of a taste recognition memory. Notably, the D1-like receptor activity into the IC is required to consolidate both innate and learned aversive taste memories but not appetitive taste memory.
味觉记忆涉及通过味觉神经网络的可塑性变化来存储信息，这些神经网络包括岛叶皮质（IC）和腹侧被盖区（VTA），后者是多巴胺的关键供应源。尽管已经证实存在一条VTA-IC多巴胺能通路，但其在巩固味觉识别记忆中的作用仍知之甚少。我们发现，对TH-Cre小鼠的VTA或VTA-IC多巴胺能终末中的多巴胺能神经元进行光刺激，可提高显著性，从而巩固阈下的新味觉刺激，而不管其享乐价值如何，且不会改变它们的味觉适口性。重要的是，向IC中抑制D1样受体，会损害显著性，从而不利于巩固厌恶味觉识别记忆。最后，我们的结果表明，VTA光刺激通过IC中的D1样受体提高显著性，以巩固条件性味觉厌恶记忆。得出的结论是，从VTA到IC的多巴胺活性是增加显著性所必需的，而显著性是巩固味觉识别记忆所必需的。值得注意的是，IC中的D1样受体活性是巩固先天性和习得性厌恶味觉记忆所必需的，但不是巩固偏好性味觉记忆所必需的。
