Am J Psychiatry. 2013 Oct;170(10):1143-51. doi: 10.1176/appi.ajp.2013.11111745.
Recent studies suggest that altered function of higher-order appetitive neural circuitry may contribute to restricted eating in anorexia nervosa and overeating in bulimia nervosa. This study used sweet tastes to interrogate gustatory neurocircuitry involving the anterior insula and related regions that modulate sensory-interoceptive-reward signals in response to palatable foods.
Participants who had recovered from anorexia nervosa and bulimia nervosa were studied to avoid confounding effects of altered nutritional state. Functional MRI measured brain response to repeated tastes of sucrose and sucralose to disentangle neural processing of caloric and noncaloric sweet tastes. Whole-brain functional analysis was constrained to anatomical regions of interest.
Relative to matched comparison women (N=14), women recovered from anorexia nervosa (N=14) had significantly diminished and women recovered from bulimia nervosa (N=14) had significantly elevated hemodynamic response to tastes of sucrose in the right anterior insula. Anterior insula response to sucrose compared with sucralose was exaggerated in the recovered group (lower in women recovered from anorexia nervosa and higher in women recovered from bulimia nervosa).
The anterior insula integrates sensory reward aspects of taste in the service of nutritional homeostasis. One possibility is that restricted eating and weight loss occur in anorexia nervosa because of a failure to accurately recognize hunger signals, whereas overeating in bulimia nervosa could represent an exaggerated perception of hunger signals. This response may reflect the altered calibration of signals related to sweet taste and the caloric content of food and may offer a pathway to novel and more effective treatments.
最近的研究表明，高级食欲神经回路功能的改变可能导致厌食症患者的摄食受限和贪食症患者的过度进食。本研究使用甜味来探究涉及前岛叶和相关区域的味觉神经回路，这些区域调节对美味食物的感觉-内脏-奖励信号。
研究了从厌食症和贪食症中恢复的参与者，以避免营养状态改变的混杂影响。功能磁共振成像（fMRI）测量了对蔗糖和三氯蔗糖重复味觉的大脑反应，以分离热量和非热量甜味的神经处理。全脑功能分析受限于解剖学感兴趣区域。
与匹配的对照组女性（N=14）相比，从厌食症中恢复的女性（N=14）右侧前岛叶对蔗糖味觉的血流动力学反应明显减弱，从贪食症中恢复的女性（N=14）则明显升高。前岛叶对蔗糖的反应与三氯蔗糖的反应相比在恢复组中被夸大（厌食症恢复女性的反应较低，贪食症恢复女性的反应较高）。
前岛叶整合了味觉的感官奖励方面，以维持营养平衡。一种可能性是，厌食症患者由于未能准确识别饥饿信号而导致摄食受限和体重减轻，而贪食症患者的过度进食可能代表对饥饿信号的过度感知。这种反应可能反映了与甜味和食物热量相关的信号的改变校准，并且可能为新的、更有效的治疗方法提供途径。
