Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience King's College London, London, UK.
Centre for Obesity Research, Department of Medicine, University College London, London, UK.
Hum Brain Mapp. 2022 Dec 15;43(18):5432-5451. doi: 10.1002/hbm.26019. Epub 2022 Jul 21.
Aberrant responses within homeostatic, hedonic and cognitive systems contribute to poor appetite control in those with an overweight phenotype. The hedonic system incorporates limbic and meso-limbic regions involved in learning and reward processing, as well as cortical regions involved in motivation, decision making and gustatory processing. Equally important within this complex, multifaceted framework are the cognitive systems involved in inhibitory control and valuation of food choices. Regions within these systems display insulin receptors and pharmacologically increasing central insulin concentrations using intranasal administration (IN-INS) has been shown to significantly reduce appealing food cue responsiveness and also food intake. In this work we describe a placebo-controlled crossover pharmacological functional magnetic resonance imaging (fMRI) study that looks at how IN-INS (160 IU) affects anticipatory and consummatory responses to sweet stimuli and importantly how these responses differ between healthy normal weight and overweight male individuals. This work shows that age matched normal weight and overweight (not obese) individuals respond similarly to both the anticipation and receipt of sweet stimuli under placebo conditions. However, increased central insulin concentrations produce marked differences between groups when anticipating sweet stimuli within the prefrontal cortex and midbrain as well as observed differences in the amygdala during consummatory responses.
在具有超重表型的人群中，体内平衡、愉悦和认知系统的异常反应导致食欲控制不良。愉悦系统包括参与学习和奖励处理的边缘和中边缘区域，以及涉及动机、决策和味觉处理的皮质区域。在这个复杂的、多方面的框架内同样重要的是涉及抑制控制和食物选择评估的认知系统。这些系统内的区域显示出胰岛素受体，并且通过鼻内给药（IN-INS）药理学增加中枢胰岛素浓度已被证明可显著降低诱人食物线索的反应性，同时也减少食物摄入。在这项工作中，我们描述了一项安慰剂对照交叉药理学功能磁共振成像（fMRI）研究，该研究着眼于 IN-INS（160IU）如何影响对甜味刺激的预期和享受反应，以及这些反应在健康正常体重和超重男性个体之间的差异。这项工作表明，年龄匹配的正常体重和超重（非肥胖）个体在安慰剂条件下对甜味刺激的预期和接受反应相似。然而，当在额皮质和中脑内预期甜味刺激时，增加中枢胰岛素浓度会在组间产生明显差异，并且在享受反应期间在杏仁核中观察到差异。
