Irving Zoe R, Greiner Eliza M, Indriolo Mark, Liu Zhe, Petrovich Gorica D
Department of Psychology and Neuroscience, Boston College, Chestnut Hill, MA, 02467, USA.
Brain Struct Funct. 2025 May 22;230(5):73. doi: 10.1007/s00429-025-02927-3.
Novelty has significant effects on feeding behavior. New foods and unfamiliar environments suppress consumption, and adaptation to novelty is fundamental to survival. Yet, little is known about habituation to eating in a novel environment. The aim of the current study was to determine if context familiarity impacts habituation to novel food and to identify underlying neural substrates. Adult male and female rats were tested for consumption of a novel, palatable food in a novel or familiar environment across four habituation sessions and a final test session. Test-induced Fos expression was measured in amygdalar, thalamic, prefrontal, and hippocampal regions known to be recruited during the first exposure to novelty. Rats in the novel context ate less compared to rats in the familiar context during each habituation session and test, and females ate less than males during the first session. Habituation to eating in the novel context robustly induced Fos in the majority of regions analyzed, including the central, basolateral, and basomedial nuclei of the amygdala, thalamic paraventricular and reuniens nuclei, and the hippocampal field CA1. Females had overall higher Fos induction in most regions analyzed and higher in the novel condition in the reuniens nucleus. Bivariate correlation analyses of Fos induction between regions found a large number of correlations in the novel context condition. Females tested in the novel context had uniquely large number of correlations between all regions analyzed, except for one thalamic subregion. These results suggest that novelty from context remains relevant late in habituation and recruits a distinct and more interactive network in females than in males.
新奇性对进食行为有显著影响。新食物和陌生环境会抑制进食，而适应新奇性是生存的基础。然而，对于在新环境中进食的习惯化知之甚少。本研究的目的是确定环境熟悉度是否会影响对新食物的习惯化，并确定潜在的神经基质。成年雄性和雌性大鼠在四个习惯化阶段和一个最终测试阶段，于新环境或熟悉环境中对一种新奇、可口的食物的摄入量进行测试。在杏仁核、丘脑、前额叶和海马区测量测试诱导的Fos表达，这些区域在首次接触新奇事物时会被激活。在每个习惯化阶段和测试中，处于新环境中的大鼠比处于熟悉环境中的大鼠进食量少，并且在第一阶段雌性大鼠比雄性大鼠进食量少。在新环境中进食的习惯化在大多数分析区域中强烈诱导Fos表达，包括杏仁核的中央核、基底外侧核和基底内侧核、丘脑室旁核和连合核以及海马CA1区。在大多数分析区域中，雌性大鼠的Fos诱导总体上更高，在连合核的新环境条件下更高。对各区域之间的Fos诱导进行双变量相关性分析发现在新环境条件下有大量相关性。在新环境中测试的雌性大鼠，除一个丘脑亚区域外，在所有分析区域之间具有独特的大量相关性。这些结果表明，环境新奇性在习惯化后期仍然具有相关性，并且在雌性中比在雄性中招募了一个更独特、更具交互性的网络。
