奖赏环路与阿片成瘾:喙内侧被盖核的调节作用

喙内侧被盖核(RMTg)位于腹侧被盖区(VTA)的尾部, 富含抑制性的γ-氨基丁酸(GABA)能神经元.RMTg是中脑边缘多巴胺系统的一个综合调节器.它的GABA能神经元接受外侧缰核(LHb)的输入, 然后投射到VTA多巴胺能神经元, 进而抑制多巴胺的释放.这三个脑区是奖赏环路的重要组成部分, 其中RMTg在阿片类物质激活的奖赏环路中尤为重要.阿片类物质主要通过抑制RMTg GABA能神经元使VTA多巴胺能神经元去抑制, 进而激活奖赏系统.因此, RMTg有望成为治疗药物成瘾(尤其是阿片成瘾)的一个重要靶点.此外, 胆碱类物质作用于RMTg的毒蕈碱受体能够抑制阿片类物质诱导的奖赏效应.未来研究应深入探讨RMTg调控的负性奖赏环路, 这对弱化觅药动机,促进消退和戒断具有重要意义.     

Executive dysfunction affects word list recall performance: Evidence from amyotrophic lateral sclerosis and other neurodegenerative diseases

The Rey Auditory Verbal Learning Test (RAVLT) is widely used in clinical practice to evaluate verbal episodic memory. While there is evidence that RAVLT performance can be influenced by executive dysfunction, the way executive disorders affect the serial position curve (SPC) has not been yet explored. To this aim, we analysed immediate and delayed recall performances of 13 non‐demented amyotrophic lateral sclerosis (ALS) patients with a specific mild executive dysfunction (ALSci) and compared their performances to those of 48 healthy controls (HC) and 13 cognitively normal patients with ALS. Moreover, to control for the impact of a severe dysexecutive syndrome and a genuine episodic memory deficit on the SPC, we enrolled 15 patients with a diagnosis of behavioural variant of frontotemporal dementia (bvFTD) and 18 patients with probable Alzheimer's disease (AD). Results documented that, compared to cognitively normal subjects, ALSci patients had a selective mid‐list impairment for immediate recall scores. The bvFTD group obtained low performances with a selectively increased forgetting rate for terminal items, whereas the AD group showed a disproportionately large memory loss on the primary and middle part of the SPC for immediate recall scores and were severely impaired in the delayed recall trial. These results suggested that subtle executive dysfunctions might influence the recall of mid‐list items, possibly reflecting deficiency in control strategies at retrieval of word lists, whereas severer dysexecutive syndrome might also affect the recall of terminal items possibly due to attention deficit or retroactive interference.     

脐血干细胞移植治疗肌萎缩侧索硬化伦理问题的思考

肌萎缩侧索硬化症是神经系统一种致死性疾病,目前尚无有效治疗方法,脐血干细胞移植为其生存带来了希望。详细论述了脐血、干细胞与伦理学,肌萎缩侧索硬化与生命伦理学的关系,以及如何在肌萎缩侧索硬化治疗中体现生命伦理学的核心精神。面对脆弱的生命,医务人员、伦理学者和管理部门应该如何为此类疾病患者生命和健康作出应尽的职责。     

保留的跨通道启动与老化：对于近期观点的总结

通道内重复启动的研究提示老年人内隐记忆未受损, 这不只体现在视觉通道上还包括其他感觉通道(例如触觉、听觉和嗅觉)。然而很少有研究考察启动任务是否具有通道特异性。在以年轻人为被试的研究中发现跨通道迁移(视觉到触觉和触觉到视觉)和通道内迁移(视觉到视觉, 触觉到触觉)具有相似性。一项最近的研究进一步探索老年人在跨通道启动任务上是否受损。结果显示视觉和触觉间的跨通道启动在年轻被试和老年被试上都是保留的且具有对称性。并且, 对于自然声响、图片的通道内和跨通道启动任务随着年老化发展仍旧保留。这些行为结果和其它最近神经科学结果显示跨通道启动发生于枕叶后纹状皮层区, 而这一区域在老年人中未损坏。这一领域未来的研究方向包括利用不同知觉通道间、利用熟悉的和新异的刺激并结合行为的和脑成像的方法, 通过设计完善的跨通道启动来研究正常老人与阿尔兹海默病人, 还包括将设计得完善的启动任务包括在用于改善老年人记忆功能的项目中。     

Midbrain-hypothalamic interrelationships in the control of aggressive behavior

Previous studies have suggested an involvement of the midbrain ventral tegmental area in the biting attack upon a rat elicited by electrical stimulation of the lateral hypothalamus in cats. In order assess further the relationship between these two regions, 12 cats were implanted with attack-eliciting electrodes in both the lateral hypothalamus and the midbrain ventral tegmental area. Following a lesion of the midbrain attack site, attack previously elicited from hypothalamic electrodes ipsilateral to the lesion was eliminated or significantly reduced in frequency. The attack elicited from electrodes in the hypothalamus contralateral to the lesion was unaffected. Midbrain lesions made at sites from which attack was never elicited had no effect on hypothalamically elicited attack. The midbrain lesion in some cases eliminated only certain components of the total attack pattern; for example, the approach of a cat to the rat frequently remained present while the bite was absent. Additionally, it was found that the attack elicited from rostral hypothalamic electrodes was disrupted to a greater degree by a single midbrain lesion than the attack elicited from more caudal hypothalamic electrodes. These finding are discussed in terms of the neural system mediating this form of aggressive behavior in cats.     

Self-control in adult humans: variation in positive reinforcer amount and delay.

In five experiments, choice responding of female human adults was examined, as a function of variations in reinforcer amount and reinforcer delay. Experiment 1 used a discrete-trials procedure, and Experiments 2, 3, 4, and 5 used a concurrent variable-interval variable-interval schedule. Reinforcer amount and reinforcer delay were varied both separately and together. In contrast to results previously reported with pigeons, the subjects in the present experiments usually chose the larger reinforcers even when those reinforcers were delayed. Together, the results from all the experiments suggest that the subjects followed a maximization strategy in choosing reinforcers. Such behavior makes it easy to observe self-control and difficult to observe impulsiveness in traditional laboratory experiments that use adult human subjects.     

外侧缰核作用于抑郁的神经生理机制

本文旨在梳理国内外有关外侧缰核作用于抑郁神经生理机制的研究成果,以期为今后抑郁研究提供借鉴和参考。首先,阐明了外侧缰核的过度兴奋会加强对下游奖赏中心单胺能脑区的抑制从而诱发抑郁的内在通路。然后,进一步论述了介导外侧缰核过度兴奋的分子机制。最后,未来要重点以人类为被试,采用纵向设计,加强外侧缰核对抑郁的影响、作用机制及其性别差异的研究,同时考察遗传基因和环境在其间的调控效应等问题。     

Expressive disclosure to improve well-being in patients with amyotrophic lateral sclerosis: A randomised,controlled trial

Amyotrophic lateral sclerosis (ALS) is a terminal neurological disease associated with progressive paralysis, loss of communicative ability and functional decline. Expressive disclosure may help people with ALS, particularly those who are emotionally or socially inhibited, meet psychological challenges associated with the disease. People with ALS (N?=?48) were randomised to expressive disclosure about their disease or no disclosure. Psychological well-being (affect, depression and quality of life) was assessed pre-intervention and also three and six months later. Results of multi-level models indicated that the group that disclosed thoughts and feelings about ALS had higher well-being than the control group at three months post-intervention, but not six months. Ambivalence over emotional expression (AEE) moderated three-month post-intervention well-being. Those low in AEE had higher well-being than those high in AEE regardless of condition. Those high in AEE, who disclosed, had increased well-being from pre-intervention, whereas controls had decreased well-being from pre-intervention. Expressive disclosure may be helpful for people with ALS, but only those who have difficulty expressing emotions. In addition, the intervention had only temporary effects; the dynamic challenges of ALS progression may mean that the effect of processing thoughts and feelings about the disease in one stage may not generalise to later stages.     

Psychological wellbeing and quality of life in amyotrophic lateral sclerosis: A review

Amyotrophic lateral sclerosis is a fatal neurodegenerative disease with a progressive and rapid course that, so far, cannot be stopped or reversed. The psychological impact of the disease is huge, on both patients and caregivers. This review summarizes studies that have investigated quality of life, depression, anxiety, pain, spiritual and existential issues, hope, and hopelessness in the ALS field, with attention to both patients and their caregivers. Psychological support and the possible role of psychologists in the ALS field are also discussed.     

社会决策中的公平准则及其神经机制

社会决策中的公平准则一直受到广泛的关注,经济学家和心理学家们分别从动机和认知的角度对这个课题进行了深入探索.在这些工作中,最为突出的是“均等”,“互惠”和“情绪”三个模型的提出.均等和互惠模型试图从动机角度理解个体的公平行为,而情绪模型则更强调个体在公平决策中的认知和情绪的加工过程.近年来脑成像的研究也为这些模型提供了相应的支持,其中与公平准则最密切的脑区是脑岛和背外侧前额叶:前者一般被认为是反映了个体面对不公平待遇时的负性情绪体验;而后者主要负责决策过程中的抑制控制.但这些脑区具体的功能还存在很多争议,反映了不同理论模型对特定脑区功能的不同理解.未来研究应注意三个模型之间的相互补充,以及加强多模态的脑指标的运用,并注重相关脑区的整体性,此外,公平决策行为中的个体差异,以及社会情境对其的影响也应受到重视.