Department of Psychiatry, Columbia University, College of Physicians & Surgeons, New York, NY, USA.
Neuroscience. 2012 May 3;209:128-35. doi: 10.1016/j.neuroscience.2012.02.030. Epub 2012 Feb 24.
Reductions in reward-related (e.g. striatal) neural activation have been noted following obesity surgery. It has been speculated that these postoperative neural changes may be related to documented postoperative changes in food preferences; however, this relation has not been previously established. In this study, functional magnetic resonance imaging and rating scales were used to assess neural responsivity, desire to eat (i.e. wanting), and liking for high- and low-calorie food cues in 14 females one month pre- and one month post-Roux-en-Y gastric bypass (RYGB) surgery. Pre- to post-RYGB changes in all variables were assessed, and postoperative changes in neural responsivity were regressed on postoperative changes in desire to eat and liking of foods. Results revealed significant postoperative reductions in mesolimbic (e.g. striatal) neural responsivity, desire to eat (wanting), and liking for high- relative to low-calorie food cues. Postoperative reductions in mesolimbic responsivity were associated with postoperative reductions in wanting, but not liking, for high- versus low-calorie foods. Interestingly, reductions in food wanting were also related to reductions in inhibitory (e.g. dorsolateral prefrontal cortex) activation following RYGB. Results are consistent with the hypothesized delineation between wanting and liking, supporting the notion that wanting, but not liking, is processed through the dopaminergic reward pathway. Concurrent reductions in both reward-related and inhibitory activation-predicted reductions in desire to eat might suggest that less dietary inhibition was elicited to resist potential overconsumption as the anticipated reward value of high-calorie foods decreased following RYGB.
肥胖症手术后，与奖励相关的（例如纹状体）神经激活减少已被注意到。有人推测，这些术后神经变化可能与文献中记录的术后食物偏好变化有关；然而，这一关系尚未得到证实。在这项研究中，使用功能磁共振成像和评分量表来评估 14 名女性在接受 Roux-en-Y 胃旁路（RYGB）手术前一个月和手术后一个月的神经反应性、对食物的渴望（即想要）和喜好程度，以及对高卡路里和低卡路里食物线索的反应。评估了所有变量从术前到术后的变化，并将术后神经反应性的变化与术后对食物的渴望和喜好的变化进行回归分析。结果显示，中脑边缘系统（例如纹状体）的神经反应性、对食物的渴望（想要）以及对高卡路里相对低卡路里食物线索的喜好都有明显的术后下降。中脑边缘反应性的术后下降与术后对高卡路里食物的渴望下降有关，而与对低卡路里食物的喜好无关。有趣的是，食物渴望的减少也与 RYGB 后抑制性（例如背外侧前额叶皮层）激活的减少有关。研究结果与对渴望和喜好之间的区别的假设相一致，支持这样的观点，即渴望而不是喜好，是通过多巴胺奖励途径来处理的。对食物的渴望减少，同时也伴随着与奖励相关的和抑制性的激活减少，这可能表明，随着预期的高卡路里食物的奖励价值在 RYGB 后降低，对饮食的抑制减少，以抵抗潜在的过度消费。
