González-Parra Jose Antonio, Acciai Vittoria, Vidal-Palencia Laura, Canela-Grimau Marc, Busquets-Garcia Arnau
Cell-Type Mechanisms in Normal and Pathological Behavior Research Group, Neuroscience Research Program, Hospital del Mar Research Institute, Barcelona 08003, Spain.
Proc Natl Acad Sci U S A. 2025 Jun 10;122(23):e2502127122. doi: 10.1073/pnas.2502127122. Epub 2025 Jun 6.
Since our first steps in life, we are forming incidental associations between diverse stimuli across various sensory modalities that influence our future choices and facilitate adaptation to environmental fluctuations. Daily behavior is usually governed by indirect incidental associations among sensory cues that have never been explicitly paired with a reinforcer. This phenomenon, known as higher-order conditioning, can be systematically investigated in laboratory animals through specific behavioral paradigms such as sensory preconditioning protocols. In this study, using "Targeted Recombination in Active Populations" (TRAP2) transgenic mice, we have interrogated which are the brain areas orchestrating the encoding of associations between olfactory and gustatory stimuli and the expression of an aversive odor-taste sensory preconditioning paradigm. We identified neuronal ensembles within the basolateral amygdala specifically activated during odor-taste associations. To demonstrate the causal involvement of this brain region in our sensory preconditioning task, we inhibited it during the preconditioning phase (i.e., incidental associations) using a chemogenetic approach, which caused a clear impairment of the mediated responses. In addition, using retrograde tracers in the basolateral amygdala of TRAP2 mice, we observed that the projections from the lateral entorhinal cortex to the basolateral amygdala are particularly activated during odor-taste associations. Notably, the chemogenetic inhibition of this brain circuit impaired the mediated aversion performance in our sensory preconditioning task. Overall, these findings highlight the amygdala as a pivotal modulator of incidental associations during an aversive sensory preconditioning task and point toward a brain circuit crucially involved in these complex cognitive processes.
从我们人生的第一步开始,我们就在不同的感觉模态中的各种刺激之间形成偶然的关联,这些关联会影响我们未来的选择,并促进我们适应环境的波动。日常行为通常受感觉线索之间间接的偶然关联所支配,这些感觉线索从未与强化物明确配对过。这种被称为高阶条件作用的现象,可以通过特定的行为范式,如感觉预适应实验方案,在实验动物身上进行系统研究。在本研究中,我们使用“活跃群体中的靶向重组”(TRAP2)转基因小鼠,探究了哪些脑区在协调嗅觉和味觉刺激之间关联的编码以及厌恶气味-味觉感觉预适应范式的表达。我们确定了基底外侧杏仁核内的神经元集群在气味-味觉关联期间被特异性激活。为了证明这个脑区在我们的感觉预适应任务中的因果作用,我们在预适应阶段(即偶然关联阶段)使用化学遗传学方法对其进行抑制,这导致介导反应明显受损。此外,在TRAP2小鼠的基底外侧杏仁核中使用逆行示踪剂,我们观察到在气味-味觉关联期间,从外侧内嗅皮质到基底外侧杏仁核的投射特别活跃。值得注意的是,对这个脑回路的化学遗传学抑制损害了我们感觉预适应任务中介导的厌恶表现。总体而言,这些发现突出了杏仁核在厌恶感觉预适应任务中作为偶然关联的关键调节因子,并指向一个在这些复杂认知过程中至关重要的脑回路。