Holsen Laura M, Lawson Elizabeth A, Christensen Kara, Klibanski Anne, Goldstein Jill M
Division of Women׳s Health, Department of Medicine, Boston, MA, USA; Department of Psychiatry, Brigham & Women׳s Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
Harvard Medical School, Boston, MA, USA; Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA.
Psychiatry Res. 2014 Aug 30;223(2):94-103. doi: 10.1016/j.pscychresns.2014.04.015. Epub 2014 May 6.
Evidence contributing to the understanding of neurobiological mechanisms underlying appetite dysregulation in anorexia nervosa draws heavily on separate lines of research into neuroendocrine and neural circuitry functioning. In particular, studies consistently cite elevated ghrelin and abnormal activation patterns in homeostatic (hypothalamus) and hedonic (striatum, amygdala, insula) regions governing appetite. The current preliminary study examined the interaction of these systems, based on research demonstrating associations between circulating ghrelin levels and activity in these regions in healthy individuals. In a cross-sectional design, we studied 13 women with active anorexia nervosa (AN), 9 women weight-recovered from AN (AN-WR), and 12 healthy-weight control women using a food cue functional magnetic resonance imaging paradigm, with assessment of fasting levels of acylated ghrelin. Healthy-weight control women exhibited significant positive associations between fasting acylated ghrelin and activity in the right amygdala, hippocampus, insula, and orbitofrontal cortex in response to high-calorie foods, associations which were absent in the AN and AN-WR groups. Women with AN-WR demonstrated a negative relationship between ghrelin and activity in the left hippocampus in response to high-calorie foods, while women with AN showed a positive association between ghrelin and activity in the right orbitofrontal cortex in response to low-calorie foods. Findings suggest a breakdown in the interaction between ghrelin signaling and neural activity in relation to reward responsivity in AN, a phenomenon that may be further characterized using pharmacogenetic studies.
有助于理解神经性厌食症食欲调节异常背后神经生物学机制的证据,在很大程度上依赖于对神经内分泌和神经回路功能的不同研究方向。特别是,研究一致指出,在调节食欲的稳态(下丘脑)和享乐(纹状体、杏仁核、脑岛)区域,胃饥饿素水平升高以及激活模式异常。基于在健康个体中循环胃饥饿素水平与这些区域活动之间存在关联的研究,当前的初步研究考察了这些系统之间的相互作用。在一项横断面设计中,我们使用食物线索功能磁共振成像范式,对13名患有活动性神经性厌食症(AN)的女性、9名从AN中恢复体重的女性(AN-WR)和12名健康体重的对照女性进行了研究,并评估了酰基化胃饥饿素的空腹水平。健康体重的对照女性在对高热量食物的反应中,空腹酰基化胃饥饿素与右侧杏仁核、海马体、脑岛和眶额皮质的活动之间呈现出显著的正相关,而在AN组和AN-WR组中不存在这种关联。AN-WR组的女性在对高热量食物的反应中,胃饥饿素与左侧海马体的活动之间呈现出负相关,而AN组的女性在对低热量食物的反应中,胃饥饿素与右侧眶额皮质的活动之间呈现出正相关。研究结果表明,在AN中,胃饥饿素信号与神经活动之间关于奖赏反应性的相互作用出现了中断,这一现象可能可以通过药物遗传学研究进一步加以描述。