Department of Preventive Medicine, Hoglund Brain Imaging Center, The University of Kansas Medical Center, Kansas City, KS, USA.
Int J Obes (Lond). 2010 Oct;34(10):1494-500. doi: 10.1038/ijo.2010.84. Epub 2010 May 4.
To investigate the neural mechanisms of food motivation in children and adolescents, and examine brain activation differences between healthy weight (HW) and obese participants.
Ten HW children (ages 11-16; BMI < 85%ile) and 10 obese children (ages 10-17; BMI >95%ile) matched for age, gender and years of education.
Functional magnetic resonance imaging (fMRI) scans were conducted twice: when participants were hungry (pre-meal) and immediately after a standardized meal (post-meal). During the fMRI scans, the participants passively viewed blocked images of food, non-food (animals) and blurred baseline control.
Both groups of children showed brain activation to food images in the limbic and paralimbic regions (PFC/OFC). The obese group showed significantly greater activation to food pictures in the PFC (pre-meal) and OFC (post-meal) than the HW group. In addition, the obese group showed less post-meal reduction of activation (vs pre-meal) in the PFC, limbic and the reward-processing regions, including the nucleus accumbens.
Limbic and paralimbic activation in high food motivation states was noted in both groups of participants. However, obese children were hyper-responsive to food stimuli as compared with HW children. In addition, unlike HW children, brain activations in response to food stimuli in obese children failed to diminish significantly after eating. This study provides initial evidence that obesity, even among children, is associated with abnormalities in neural networks involved in food motivation, and that the origins of neural circuitry dysfunction associated with obesity may begin early in life.
研究儿童和青少年的食物动机的神经机制，并检查健康体重（HW）和肥胖参与者之间的大脑激活差异。
10 名 HW 儿童（年龄 11-16 岁；BMI<85%）和 10 名肥胖儿童（年龄 10-17 岁；BMI>95%），年龄、性别和受教育年限相匹配。
进行了两次功能性磁共振成像（fMRI）扫描：参与者饥饿时（餐前）和标准餐后立即（餐后）。在 fMRI 扫描期间，参与者被动观看食物、非食物（动物）和模糊基线对照的图像块。
两组儿童在边缘和边缘区域（PFC/OFC）均显示出对食物图像的大脑激活。与 HW 组相比，肥胖组在 PFC（餐前）和 OFC（餐后）对食物图片的激活明显更大。此外，与 HW 组相比，肥胖组在 PFC、边缘和奖赏处理区域（包括伏隔核）中的激活在餐后减少较少（与餐前相比）。
两组参与者在高食物动机状态下均出现边缘和边缘激活。然而，与 HW 儿童相比，肥胖儿童对食物刺激的反应过度。此外，与 HW 儿童不同，肥胖儿童对食物刺激的大脑反应在进食后并未明显减少。本研究首次提供证据表明，肥胖症，即使在儿童中，也与参与食物动机的神经网络异常有关，并且与肥胖相关的神经回路功能障碍的起源可能早在生命早期就开始了。
