Ethanol state-dependent memory: involvement of dorsal hippocampal muscarinic and nicotinic receptors

In the present study, the effects of bilateral injections of cholinergic agents into the hippocampal CA1 regions (intra-CA1) on ethanol state-dependent memory were examined in mice. A single-trial step-down passive avoidance task was used for the assessment of memory retention in adult male NMRI mice. Pre-training intraperitoneal injection (i.p.) of ethanol (0.25, 0.5 and 1 g/kg) dose dependently induced impairment of memory retention. Pre-test administration of ethanol (0.5 and 1 g/kg, i.p.) induced state-dependent retrieval of the memory acquired under pre-training ethanol (1 g/kg, i.p.) influence. Pre-test intra-CA1 injection of physostigmine (2.5 and 5 μg/mouse, intra-CA1) or nicotine (0.3 and 0.5 μg/mouse, intra-CA1) improved pre-training ethanol (1 g/kg)-induced retrieval impairment. Moreover, pre-test administration of physostigmine (2.5 and 5 μg/mouse, intra-CA1) or nicotine (0.3 and 0.5 μg/mouse, intra-CA1) with an ineffective dose of ethanol (0.25 g/kg) significantly restored the retrieval and induced ethanol state-dependent memory. Pre-test intra-CA1 injection of the muscarinic receptor antagonist, atropine (4 and 8 μg/mouse, intra-CA1) or the nicotinic receptor antagonist, mecamylamine (2 and 4 μg/mouse, intra-CA1) 5 min before the administration of ethanol (1 g/kg, i.p.) dose dependently inhibited ethanol state-dependent memory. Pre-test intra-CA1 administration of physostigmine (0.5, 2.5 and 5 μg/mouse), atropine (2, 4 and 8 μg/mouse), nicotine (0.1, 0.3 and 0.5 μg/mouse) or mecamylamine (1, 2 and 4 μg/mouse) alone cannot affect memory retention. These findings implicate the involvement of a dorsal hippocampal cholinergic mechanism in ethanol state-dependent memory and also it can be concluded that there may be a cross-state dependency between ethanol and acetylcholine.     

Rigidity in social and emotional memory in the R6/2 mouse model of Huntington's disease

Four experiments were conducted to examine social and emotional memory in the R6/2 transgenic mouse model of Huntington’s disease. First, R6/2 mice were tested in a social transmission of food preference task where they had to acquire a preference for a flavoured food (acquisition) and subsequently to learn a preference for a different flavour (shifted reinforcement). R6/2 mice performed well in the acquisition trial. However, they were impaired in the shifted reinforcement trial and perseverated on the first preference learned. Second, mice were trained in an inhibitory avoidance paradigm, with either one or two footshocks delivered during the training. WT mice given one footshock showed retention levels lower than those of mice trained with two footshocks. By contrast, there was no difference in retention levels of R6/2 mice given either one or two footshocks. Third, mice were tested in an active avoidance task that paired a mild footshock with a warning light. R6/2 mice had a strong age-dependent deficit in this task. Finally, mice were tested in a conditioned taste aversion task that paired a saccharine solution with a nausea-inducing agent (LiCl). R6/2 mice displayed normal aversion, however this was not extinguished following repeated exposure to saccharine solution alone. Our data show that while R6/2 mice have functional hippocampus-based memory, they have deficits in striatum-based memory skills. Further, social and emotional memories appear to be encoded in a rigid way that is not influenced by subsequent learning or by arousal levels.     

Electrical stimulation of the pedunculopontine tegmental nucleus in freely moving awake rats: time- and site-specific effects on two-way active avoidance conditioning

The pedunculopontine tegmental nucleus (PPTg) is involved in the regulation of thalamocortical transmission and of several functions related to ventral and dorsal striatal circuits. Stimulation of the PPTg in anesthetized animals increases cortical arousal, cortical acetylcholine release, bursting activity of mesopontine dopaminergic cells, and striatal dopamine release. It was hypothetized that PPTg stimulation could improve learning by enhancing cortical arousal and optimizing the activity of striatal circuits. We tested whether electrical stimulation (ES) of the PPTg, applied to freely-moving awake rats previously implanted with a chronic electrode, would improve the acquisition and/or the retention of two-way active avoidance conditioning, and whether this effect would depend on the specific PPTg region stimulated (anterior vs posterior) and on the time of ES: just before (pre-training) or after (post-training) each of three training sessions. The treatment consisted of 20 min of ES (0.2 ms pulses at 100 Hz; current intensity: 40-80 microA). The results showed that (1) this stimulation did not induce either any signs of distress nor abnormal behaviors, apart from some motor stereotyped behaviors that disappeared when current intensity was lowered; (2) pre-training ES applied to the anterior PPTg improved the acquisition of two-way active avoidance, (3) no learning improvement was found after either post-training ES of the anterior PPTg, or pre- and post-training ES of the posterior PPTg. The results give support to a role of PPTg in learning-related processes, and point to the existence of functional PPTg regions.     

Uncertainty Avoidance Influences Choices for Potential Gains but not Losses

Uncertainty of outcomes is a primary dimension underlying human judgment and decision making, and is a defining feature of risk. Even though uncertainty almost always exists in decision making contexts, individuals and cultures vary in their preference for avoiding uncertainty. This study examines how uncertainty avoidance influences judgments involving uncertain and risky alternatives. Participants were presented with problems that involve potential gains or losses and contain options reflecting uncertain or certain outcomes. Greater uncertainty avoidance predicted choices for uncertain outcomes that involved gains, which tend to promote risk aversion, but not for uncertain outcomes that led to losses, which tend to promote risk seeking. These results demonstrate that culturally-relevant dispositions such as uncertain avoidance can have complex effects on judgment.     

Spatial cognition in the gerbil: computing optimal escape routes from visual threats

Previous studies in our laboratory have shown that when presented with a sudden stimulus simulating an oncoming predator, Mongolian gerbils can compute the optimal trajectory to a safe refuge, taking into account the position of the threat, the location of a clearly visible refuge, and several other contextual variables as well. In the present studies, the main goal was to explore the abilities of gerbils to use mental representations of spaces that were visually occluded by opaque barriers to compute efficient escape trajectories. In all studies, gerbils were placed into a round open field containing a single refuge. On each trial, an overhead visual stimulus was caused to ‘fly’ overhead, eliciting robust escape movements from the gerbils. By manipulating the shape and position of a series of opaque barriers that were interposed between the gerbils and the refuge, we were able to show that gerbils can compute the shortest route to an invisible target, even when the available routes to the target are made complex by using elaborate barrier shapes. These findings suggest that gerbils can maintain representations of their locations with respect to salient environmental landmarks and refuges, even when such locations are not continuously visible.     

儿童社交回避行为：成因、测量方式及适应功能

社会退缩行为是指儿童在社会情境中抑制自己参与同伴互动并表现出独处的行为。根据不同的社交动机,社会退缩行为包含多种亚类型,其中社交回避行为这一亚类型指儿童总是表现出主动避免各种社交场合的行为。总体而言,社交回避是目前研究最少的一种,其形成的主要原因可能是由于儿童本身较高的抑郁感所致,而研究者已开始尝试以间接和直接的方式测量其水平。来自以变量为中心和以个体为中心的研究分别表明,社交回避儿童面临着最高的适应风险。鉴于这一研究领域的广泛前景,未来的研究亟需关注社交回避影响儿童适应的过程机制及其年龄发展特点,测量工具的进一步开发,直接的跨文化比较以及社交回避的干预方案开发。     

神经质对青少年情绪化饮食的影响：一个有调节的中介效应模型

摘 要 为探讨神经质、青少年情绪化饮食、体验回避及自尊之间的关系,选取1000名青少年为被试,采用简式大五人格问卷、荷兰饮食行为问卷、接纳行动量表及自尊量表进行测试。结果表明：（1）神经质对青少年情绪化饮食有显著的正向影响,并间接地通过体验回避对青少年情绪化饮食产生作用;（2）自尊在体验回避对青少年情绪化饮食的影响中起显著的调节作用,具体而言,在低自尊水平下,体验回避能显著地正向预测青少年情绪化饮食,而在高自尊水平下,体验回避对青少年情绪化饮食的预测作用不显著。     

交互视角下工作重塑干预的影响效应整合模型

作为一种引导员工主动改变工作的行为, 工作重塑干预成为近年来组织行为学领域研究的重要主题。基于现有研究成果, 系统梳理了工作重塑干预的概念和分类。依据角色-资源接近-回避模型, 归纳和提炼了工作干预的影响效果, 在此基础上, 借鉴AMO理论, 分别从重塑能力(Ability)、重塑动机(Motivation)和重塑机会(Opportunity)层面, 构建了个体和组织交互情境下的工作重塑干预内在影响机制, 进而提出了一个整合性的理论分析框架, 为当前开展工作重塑干预的相关研究提供一定的借鉴和参考。未来研究应更多关注基于中国情境的工作重塑干预影响因素及作用机制。     

自我同情对大学生拖延行为的影响：经验回避和羞耻的链式中介作用

为探讨自我同情对拖延的影响及其作用机制,采用自我同情量表、大学生拖延量表、大学生羞耻量表和接纳与行动量表对795名大学生进行调查,结果发现：(1)自我同情对大学生拖延行为具有负向预测作用;(2)羞耻在自我同情与大学生拖延行为的负向效应中起到中介作用;(3)经验回避、羞耻在自我同情和大学生拖延行为之间起链式中介作用。     

社交焦虑大学生情绪调节灵活性：情绪内容对策略选择和使用的影响

尽管社交焦虑个体被认为存在情绪调节灵活性的不足,但至今尚不清楚这种不足究竟在于难以灵活选择策略,还是难以灵活使用策略,抑或二者兼有？对此,本研究采用情绪调节策略选择任务考察了37名高社交焦虑大学生和29名低社交焦虑大学生在面对社交-非社交情绪图片时对认知重评-回避策略的选择模式和使用效果。结果发现：在面对社交情绪图片时,高社交焦虑被试比低社交焦虑被试更少选择认知重评,而更多选择回避;在面对非社交情绪图片时,两组被试对两种策略的选择模式无显著差异。同时,无论面对社交还是非社交情绪图片,两组被试对两种策略的使用效果也无显著差异。以上结果表明,相比低社交焦虑个体,高社交焦虑个体只有在面对社交情绪刺激时才存在情绪调节灵活性的不足,且这种不足主要在于难以灵活选择策略,而非难以灵活使用策略。