Department of Psychology, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA.
Surg Obes Relat Dis. 2012 Sep-Oct;8(5):602-8. doi: 10.1016/j.soard.2011.07.006. Epub 2011 Jul 27.
Adjustable gastric banding is an effective weight-loss treatment, but little is known about the neural mechanisms underlying weight loss. The purpose of the present study was to determine whether gastric banding affects brain function in regions previously implicated in food motivation, reward, and cognitive control. The setting for the study was the University of Missouri-Kansas City, Department of Psychology; Hoglund Brain Imaging Center, University of Kansas Medical Center; and private practice in the United States.
Ten obese participants were recruited before adjustable gastric banding surgery (mean body mass index before surgery 40.6 ± 1.96 kg/m2). Their mean body mass index at 12 weeks after surgery was 36.1 ± 2.32 kg/m2, with a mean percentage of excess weight loss of 25.21% ± 8.41%. Functional magnetic resonance imaging scans were conducted before and 12 weeks after adjustable gastric banding surgery. At each assessment point, the participants completed questionnaires assessing food motivation and were scanned while hungry (before eating) and immediately after a standardized meal (after eating). During the functional magnetic resonance imaging scans, the participants viewed food pictures, nonfood pictures (animals), and blurred baseline control pictures. The functional magnetic resonance imaging data were analyzed using BrainVoyager QX.
After surgery, the participants reported significantly less food motivation and more cognitive restraint. The participants also showed decreased brain activation to food versus nonfood pictures in regions implicated in food motivation and reward, including the parahippocampus, medial prefrontal cortex, insula, and inferior frontal gyrus. In contrast, they demonstrated increased activation to food versus nonfood pictures in anterior prefrontal cortex, a region implicated in cognitive control and inhibition.
This is the first study to examine the functional brain changes after gastric banding surgery and 1 of the first studies to longitudinally examine neural changes associated with weight loss. These results have provided preliminary evidence that adjustable gastric banding alters brain function in regions known to regulate reward and cognitive control.
可调节胃束带术是一种有效的减肥治疗方法，但对于减肥的神经机制知之甚少。本研究的目的是确定胃束带术是否会影响先前与食物动机、奖励和认知控制相关的大脑区域的功能。该研究的地点是密苏里堪萨斯城大学心理学系、堪萨斯大学医学中心的 Hoglund 脑成像中心以及美国的私人诊所。
在可调节胃束带手术前招募了 10 名肥胖参与者（手术前平均体重指数为 40.6±1.96kg/m2）。他们手术后 12 周的平均体重指数为 36.1±2.32kg/m2，平均超重减轻率为 25.21%±8.41%。在可调节胃束带手术后进行功能性磁共振成像扫描。在每个评估点，参与者完成了评估食物动机的问卷，并在饥饿时（进食前）和标准化餐后立即（进食后）进行了扫描。在功能性磁共振成像扫描期间，参与者观看了食物图片、非食物图片（动物）和模糊的基线对照图片。使用 BrainVoyager QX 分析功能性磁共振成像数据。
手术后，参与者报告的食物动机明显减少，认知约束增加。参与者还表现出与食物与非食物图片相比，与食物动机和奖励相关的区域（包括海马旁回、内侧前额叶皮质、岛叶和下额回）的大脑活动减少。相比之下，他们表现出与食物与非食物图片相比，与认知控制和抑制相关的前前额叶皮质的大脑活动增加。
这是第一项研究胃束带手术后功能性大脑变化的研究，也是第一项研究与体重减轻相关的神经变化的研究之一。这些结果初步证明了可调节胃束带术改变了与奖励和认知控制相关的大脑区域的功能。
