COMT基因rs6267多态性与青少年期亲子亲合与冲突的关系：性别与父母教养行为的调节作用分析

采用基因－环境设计, 以208名初中生为被试, 系统考察COMT基因rs6267多态性与青少年期亲子亲合与冲突的关系, 以及性别与父母教养行为在其中的调节作用。结果显示rs6267多态性对亲子关系无显著主效应, 但其与亲子亲合、母子情绪冲突的关联模式在男女青少年群体中相反; rs6267多态性与父母积极教养行为对亲子关系无显著交互作用, 但其与母亲消极教养行为对母子冲突具有交互作用趋势。     

5-HTR1A基因rs6295多态性与父母教养行为对青少年早期抑郁的交互作用:不同易感性模型的验证

以"不同易感性模型"为理论基础,1323名青少年为被试(初次测评时M=11.31岁;SD=0.49),考察了5-HTR1A基因rs6295多态性与父母教养行为对青少年早期抑郁的交互作用及其性别差异。结果表明:当父母积极教养行为水平较高时,携带CC基因型的女青少年抑郁水平显著低于G等位基因携带者,当父母积极教养行为水平较低时,携带不同基因型的女青少年的抑郁水平无显著差异,但rs6295多态性与父母教养行为对男青少年的抑郁无显著交互作用。此外,rs6295多态性对男女青少年早期抑郁均无显著主效应。研究结果提示,rs6295多态性与父母教养行为对青少年早期抑郁的交互作用部分支持不同易感性模型观点,且存在性别差异,主要表现于女青少年群体中。本研究发现能够为基因-环境交互作用设计研究提供一定启示,同时亦能推进有关抑郁发生机制的研究。     

超重/肥胖个体工作记忆的神经机制及干预

全球超重/肥胖人群增长迅猛,1997年世界卫生组织将肥胖认定为全球性流行病。目前,中国成年人的超重/肥胖发生率已超过50%,不健康的饮食行为占肥胖成因的70%。本项目拟从食物特异工作记忆切入,探明超重/肥胖个体食物特异工作记忆的神经机制,以及与一般工作记忆神经机制的差异。再采用前瞻性的研究设计,考察食物特异工作记忆与超重/肥胖发展的渐变关系,探索食物特异工作记忆及其神经活动对个体饮食管理和体质变化的预测作用。最后,采用食物特异抑制控制训练,提升超重/肥胖个体的食物特异工作记忆能力,塑造健康饮食行为。本项目旨在探索塑造健康饮食行为的安全及有效的方法,为超重/肥胖的预防和干预提供理论和实践建议,具有现实性、前沿性和前瞻性。     

努力：成本还是奖赏?

努力(Effort)与奖赏系统关系密切。当前关于努力在奖赏加工中的作用存在两个截然相反的观点：努力是一种成本还是一种奖赏?理论模型包括：其一, 努力是一种成本, 会降低奖赏的价值, 相应的理论解释包括内部成本模型、机会成本模型及信号模型等; 其二, 努力能够提升奖赏的价值, 相应的理论解释包括认知失调和努力的合理化模型、习得性勤奋理论及认知需求理论等。这两种观点均得到了来自于动物学、行为学、电生理学以及神经影像学等证据的支持。未来研究需要对努力准确定义, 从时间进程角度对努力的理论进行整合, 进一步考察努力的相关影响因素。     

COMT基因Val158Met多态性与抑郁的关系

抑郁的发生具有重要的遗传学基础。COMT基因Val158Met多态性是抑郁的重要候选基因位点。目前有关COMT基因Val158Met多态性与抑郁关系的研究主要采用单基因设计、单基因-环境设计以及多基因-环境设计。有资料显示负性情绪偏向及其相关脑区可能在COMT基因Val158Met多态性与抑郁间起中介作用, 但具体机制仍有待探究。未来研究可以进一步考察被试的种族、年龄和性别等因素对COMT基因Val158Met多态性与抑郁关系的调节作用, 并通过采用多基因-环境设计, 综合运用积极与消极环境指标等措施深入考察负性情绪偏向和相关脑区在COMT基因Val158Met多态性与抑郁间的作用及其机制。     

奖赏敏感性在冲动性饮食行为中的作用

肥胖会导致癌症、心脏病、糖尿病等诸多健康问题,而冲动性饮食是肥胖的一个重要影响因素。厘清奖赏敏感性在冲动性饮食中的作用,有助于深入理解冲动性饮食行为。本文介绍了奖赏敏感性的概念、涉及的主要研究领域、生物学基础及测量;整理归纳出奖赏敏感性影响冲动性饮食的三种可能路径:通过注意力偏向影响对享乐性食品的感知、影响消费欲望及随后的自我控制;文章最后指出了基于奖赏敏感性对冲动性饮食进行拓展研究的可能方向。     

MAOA基因rs6323多态性与母亲支持性教养对青少年抑郁的交互作用：素质-压力假说与不同易感性假说的检验

抑郁的遗传与环境交互作用(G×E)机制已成为富有挑战性的前沿课题之一。然而,既有G×E研究大多关注遗传基因与不利环境的交互作用,相对忽视了积极环境的影响。本研究以1025名青少年为被试,运用问卷法与 DNA分型技术,采用间隔3年的追踪设计(T1小学六年级—T2初中三年级),考察 MAOA基因rs6323多态性与母亲支持性教养对青少年抑郁的交互作用以及性别在其中的调节作用,并同时采用新兴的探索性与验证性方法检验G×E交互作用的素质–压力假说与不同易感性假说。结果显示, MAOA基因rs6323多态性与母亲支持性教养行为交互作用于女青少年的抑郁,母亲支持性教养显著负向预测 GG 基因型女青少年的抑郁,但对 TT基因型女青少年抑郁的预测作用并不显著,该交互作用符合不同易感性假说。MAOA基因 rs6323多态性与母亲支持性教养对男青少年的抑郁无显著交互作用。本研究发现推进了抑郁遗传机制的研究,并为不同易感性假说提供新的研究证据。     

COMT基因rs6267多态性与母亲教养行为对青少年身体攻击和关系攻击的交互作用

遗传与环境如何交互作用影响儿童青少年的攻击行为是当前攻击研究中的重要前沿课题之一。近年来, 分子遗传学关于人类攻击的研究已拓展到对不同攻击亚类(身体攻击和关系攻击)的遗传基础的探讨。本研究运用问卷法与DNA分型技术, 对1258名儿童进行为时4年(四年级—七年级)的追踪调查, 考察COMT基因rs6267多态性与母亲教养行为对青少年身体攻击和关系攻击的交互作用以及性别在其中的调节作用。结果发现, COMT基因rs6267多态性与母亲教养行为仅交互作用于男青少年的身体攻击, 母亲教养行为显著预测GG 基因型男青少年的身体攻击, 但对T等位基因男青少年身体攻击的预测作用并不显著。COMT基因rs6267多态性与母亲教养行为对青少年关系攻击的交互作用不显著。本研究结果表明, 身体攻击和关系攻击具有不同遗传基础和发生机制。     

父母教养与MAOA基因rs6323多态性对学前儿童外化问题的共同作用

采用G×E交互作用的研究范式,以295名学前儿童（M=4.49）和其母亲、父亲作为研究对象,探讨母亲和父亲的教养方式与MAOA基因rs6323多态性对学前儿童外化问题行为的影响。结果发现：母亲、父亲教养方式和MAOA基因多态性对学前儿童外化问题行为的影响存在性别差异,预测男孩外化问题行为时,母亲和父亲教养方式的主效应显著,与MAOA基因多态性的交互作用不显著;在预测女孩外化问题行为时,父亲教养方式的主效应显著,母亲教养方式与MAOA基因多态性的交互作用显著,显著性区域分析发现,携带T等位基因的女孩更容易受到母亲消极教养的不利影响而产生更多外化问题行为,也更容易受到其积极教养的有利影响而减少外化问题行为,这一结果支持差别易感性理论模型。     

CHRM2基因rs1824024多态性与青少年早期抑郁的关系

运用问卷法与DNA分型技术,以127名高和低抑郁组初中生为被试,考察CHRM2基因rs1824024多态性与青少年早期抑郁的关系,重点探讨负性生活事件、青少年性别与年级的调节作用。结果发现,CHRM2基因rs1824024多态性与女青少年的抑郁边缘显著关联,T等位基因携带者患高抑郁的风险较低,但该位点与男青少年的抑郁无关;在那些经历低水平负性生活事件的青少年中,T等位基因携带者患高抑郁的可能性边缘显著低于GG型基因携带者;rs1824024多态性与年级对青少年早期抑郁无显著交互作用。     

The Effects of a List of Food Items on Motivations to Eat in Dieters and Nondieters

A major health problem in our society is obesity, which is frequently caused by overeating or eating inappropriate foods. It has been suggested that the prevalences of food and food-related cues contribute to overeating and that dieters are particularly sensitive to food stimuli. In the present study, the influence of dieting was examined in a representative sample of college students who were exposed to a list of written food cues or who served as controls. The list of food cues increased motivation to eat in nondieting subjects, but did not appear to influence the appetites of dieters. It may be that dieters are more resistant to the effects of more subtle food cues, even when many cues are presented sequentially.     

Food cue exposure and body image satisfaction: the moderating role of BMI and dietary restraint

Effects of cue exposure to high and low-caloric food on body image satisfaction and the moderating role of body mass index (BMI) and restraint were investigated in 77 lean unrestrained, lean restrained and overweight restrained females. Body (BS) and weight satisfaction (WS) were assessed before and after the cue exposure. Lean restrained participants were significantly less satisfied with their weight after cue exposure to high-caloric foods in comparison to cue exposure to low-caloric foods, whereas no such effect was present in overweight restrained and lean unrestrained participants. Low-caloric food cues did not influence WS. Food cues had a nonsignificant trend effect on BS. Yet, only lean unrestrained participants experienced significantly more BS in response to food cue exposure.     

不同药物相关线索反应下感觉-运动脑区的激活及作用

药物相关线索反应不仅表现在心理渴求, 也表现在强迫性用药行为上。相关线索下, 除包括奖赏环路在内的边缘系统被激活外, 感觉-运动脑区也被激活, 引发自动化动作图式的表达, 这对相关线索反应及复吸行为具有特殊的意义。是否所有相关线索都会激活感觉-运动脑区, 目前, 还不清楚, 而这对临床治疗具有重要意义。本研究采用磁共振扫描, 生理测试等方法探索了不同类型相关线索下, 海洛因成瘾戒断者的大脑激活状况, 试图了解他们在不同线索刺激下的大脑反应。采用组内实验设计, 测量29名海洛因成瘾者相关线索反应下的血氧水平。结果发现, 相比对照线索, 所有药物相关线索, 包括药物、用药工具、用药动作线索都更多激活扣带回、海马、舌回、梭回等与奖赏机制相关的脑区; 而不同类型的药物相关线索之间的比较则显示, 用药工具和用药动作线索更多激活了双侧颞中回、双侧顶下小叶、左侧顶上小叶和右侧额下回等感觉-运动脑区。用药动作线索比单纯药物和用药工具线索, 激活了更为广泛的动作脑区。由此, 我们认为药物相关线索导致成瘾者大脑中奖赏和感觉-动作两套系统被激活, 包含用药工具、用药动作在内的相关线索会激活更多的感觉-运动脑区。     

Dietary variety, energy regulation, and obesity

Increased variety in the food supply may contribute to the development and maintenance of obesity. Thirty-nine studies examining dietary variety, energy intake, and body composition are reviewed. Animal and human studies show that food consumption increases when there is more variety in a meal or diet and that greater dietary variety is associated with increased body weight and fat. A hypothesized mechanism for these findings is sensory-specific satiety, a phenomenon demonstrating greater reductions in hedonic ratings or intake of foods consumed compared with foods not consumed. Nineteen studies documenting change in preference, intake, and hedonic ratings of food after a food has been eaten to satiation in animals and humans are reviewed, and the theory of sensory-specific satiety is examined. The review concludes with the relevance of oral habituation theory as a unifying construct for the effects of variety and sensory-specific satiety, clinical implications of dietary variety and sensory-specific satiety on energy regulation, and suggestions for future research.     

Capuchin monkeys’ use of human and conspecific cues to solve a hidden object-choice task

Learning by watching others can provide valuable information with adaptive consequences, such as identifying the presence of a predator or locating a food source. The extent to which nonhuman animals can gain information by reading the cues of others is often tested by evaluating responses to human gestures, such as a point, and less often evaluated by examining responses to conspecific cues. We tested whether ten brown capuchin monkeys (Cebus [Sapajus] apella) were able to use cues from monkeys and a pointing cue from a human to obtain hidden rewards. A monkey could gain access to a reward hidden in one of two locations by reading a cue from a conspecific (e.g., reaching) or a human pointing. We then tested whether they could transfer this skill from monkeys to humans, from humans to monkeys, and from one conspecific to another conspecific. One group of monkeys was trained and tested using a conspecific as the cue-giver and was then tested with a human cue-giver. The second group of monkeys was trained and tested with a human cue-giver and was then tested with a monkey cue-giver. Monkeys that were successful with a conspecific cue-giver were also tested with a novel conspecific cue-giver. Monkeys learned to use a human point and conspecific cues to obtain rewards. Monkeys that had learned to use the cues of a conspecific to obtain rewards performed significantly better than expected by chance when they were transferred to the cues of a novel conspecific. Monkeys that learned to use a human point to obtain rewards performed significantly better than expected by chance when tested while observing conspecific cues. Some evidence suggested that transferring between conspecific cue-givers occurred with more facility than transferring across species. Results may be explained by simple rules of association learning and stimulus generalization; however, spontaneous flexible use of gestures across conspecifics and between different species may indicate capuchins can generalize learned social cues within and partially across species.     

中国人限制性饮食和食物渴求的认知神经机制

物质丰富的时代, 如何抵御美味食物线索带来的食物渴求, 并限制饮食从而保持健康成为人们关注的重要话题之一。近年来, 国内学者为了探讨节食成功的原因, 创建中国食物图片库, 考察限制性饮食的认知神经机制, 以及成功和失败限制性饮食者的脑机制差异; 开展了特质食物渴求及中国特色的辣食渴求的认知神经研究。对推进饮食行为研究的理论发展, 也为肥胖、饮食失调等健康干预工作提供重要支持。     

Regulatory interactions of stress and reward on rat forebrain opioidergic and GABAergic circuitry

Palatable food intake reduces stress responses, suggesting that individuals may consume such ?comfort? food as self-medication for stress relief. The mechanism by which palatable foods provide stress relief is not known, but likely lies at the intersection of forebrain reward and stress regulatory circuits. Forebrain opioidergic and gamma-aminobutyric acid ergic signaling is critical for both reward and stress regulation, suggesting that these systems are prime candidates for mediating stress relief by palatable foods. Thus, the present study (1) determines how palatable ?comfort? food alters stress-induced changes in the mRNA expression of inhibitory neurotransmitters in reward and stress neurocircuitry and (2) identifies candidate brain regions that may underlie comfort food-mediated stress reduction. We used a model of palatable ?snacking? in combination with a model of chronic variable stress followed by in situ hybridization to determine forebrain levels of pro-opioid and glutamic acid decarboxylase (GAD) mRNA. The data identify regions within the extended amygdala, striatum, and hypothalamus as potential regions for mediating hypothalamic-pituitary-adrenal axis buffering following palatable snacking. Specifically, palatable snacking alone decreased pro-enkephalin-A (ENK) mRNA expression in the anterior bed nucleus of the stria terminalis (BST) and the nucleus accumbens, and decreased GAD65 mRNA in the posterior BST. Chronic stress alone increased ENK mRNA in the hypothalamus, nucleus accumbens, amygdala, and hippocampus; increased dynorphin mRNA in the nucleus accumbens; increased GAD65 mRNA in the anterior hypothalamus and BST; and decreased GAD65 mRNA in the dorsal hypothalamus. Importantly, palatable food intake prevented stress-induced gene expression changes in subregions of the hypothalamus, BST, and nucleus accumbens. Overall, these data suggest that complex interactions exist between brain reward and stress pathways and that palatable snacking can mitigate many of the neurochemical alterations induced by chronic stress.     

神经影像视角下的肥胖脑机制研究

肥胖作为一种全球性流行病,与许多慢性非传染性疾病密切相关。本文主要从脑功能和脑结构层面对现有肥胖研究做系统梳理。脑功能上,个体在加工食物线索时奖赏环路的过度激活、认知控制环路的活动缺失构成了肥胖的易感因子。脑结构上,全脑灰质体积、白质纤维束完整性和整体弥散水平的降低,从不同的影像层面提供了肥胖的神经解剖证据。未来研究可以从纵向研究的开展、干预措施的扩展和多模态脑成像数据的整合等方面展开。     

特质自我控制对食物线索注意偏向的影响及干预：来自眼动的证据

采用眼动技术,以BMI指数处于正常范围的女性为被试,考察特质自我控制对食物线索注意偏向的影响以及注意偏向训练在改变注意偏向强度上的干预效果。结果发现,对于高热量食物线索,低特质自我控制水平女性表现出了更强的注意偏向;注意偏向训练有效降低了低特质自我控制水平女性对高热量食物线索注意偏向的强度。上述结果表明,特质自我控制影响个体对食物线索的注意偏向,注意偏向训练能有效改变个体对食物线索注意偏向的强度。