Effect of vasopressin on open field and activity behavior of the vasopressin-deficient (Brattleboro) rat

The effect of 1 and 5 micrograms AVP injections on open field and photoactivity chamber behavior of D.I. and normal Long-Evans animals was studied. Administration of 5 micrograms AVP (SC) resulted in a statistically significant depression of both open field and photochamber activity in the D.I. rat, but had a less pronounced effect on normal animals. However, 1 microgram AVP resulted in only minor alterations of activity in both D.I. and normal animals. In terms of learned behavior, D.I. and normal animals displayed similar within-session habituation when comparisons were made following the same treatment conditions. Thus, this study supports the hypothesis that vasopressin may influence memory tasks by modulation of related states of emotionality, motivation, and/or attention rather than by direct involvement in the retrieval and/or consolidation of information.     

Behavioral differences between vasopressin-deficient (Brattleboro) and normal Long-Evans rats

Behavioral comparisons were made between rats of the Brattleboro strain with hereditary hypothalamic diabetes insipidus (DI) and normal Long-Evans rats. Measurements were made of activity behavior in a lighted open field and in a darkened activity chamber. Subtle measurement specific differences in the activity behavior of DI rats were found which suggested altered emotion, motivation and/or attention in the DI rats. In terms of learned behavior, DI and normal rats displayed a similar degree of habituation to all within-session activity measures in both the open field and darkened activity chamber. In a passive avoidance test, DI rats exhibited a degree of avoidance behavior equivalent to that of normal animals. Thus, these studies provide evidence that the vasopressin-deficient rat is not defective in learning and memory processes. The data can be interpreted as suggesting that vasopressin may influence memory tasks by extrinsic modulation of related states of emotionality, motivation and/or attention rather than by direct involvement in the retrieval and consolidation of information.     

基因与学习记忆调控

近年,有关基因与学习记忆调控的研究引人注目。实验显示：（１）ｃ－ｆｏｓ等即刻早期基因（ＩＥＧｓ）的激活是学习记忆形成的必要条件,长时程增强（ＬＴＰ）诱出的同时也伴有ＩＥＧｓ的激活;（２）应用转基因技术获得α－ＣａＭＫⅡ、Ｆｙｎ和Ｎ－ＣＡＭ等基因突变的小鼠,均表现明显的空间学习记忆障碍,以及ＬＴＰ诱导和维持障碍;（３）果蝇单基因（ｄｎｃ,ｒｕｔ等）突变体的学习记已能力明显下降,其机制与突触可塑性的改     

Altered alertness of vasopressin-secreting transgenic mice

We evaluated behavior and cognitive performance in a line of transgenic mice that overexpress the rat gene for vasopressin. Open field testing revealed greatest habituation in homozygous mice. Passive avoidance performance indicated equal learning and memory ability of transgenic compared to normal mice. Drinking behavior following exposure to 10% sucrose solution suggested diminished neophobia in homozygous mice. These observations are consistent with enhanced attention and alertness in the transgenic animals and support prior observations on the effects of vasopressin on behavior and cognitive function.     

Spontaneous decisions and operant conditioning in fruit flies

Already in the 1930s Skinner, Konorskiand colleagues debated the commonalities, differences and interactions among the processes underlying what was then known as “conditioned reflexes type I and II”, but which is today more well-known as classical (Pavlovian) and operant (instrumental) conditioning. Subsequent decades of research have confirmed that the interactions between the various learning systems engaged during operant conditioning are complex and difficult to disentangle. Today, modern neurobiological tools allow us to dissect the biological processes underlying operant conditioning and study their interactions. These processes include initiating spontaneous behavioral variability, world-learning and self-learning. The data suggest that behavioral variability is generated actively by the brain, rather than as a by-product of a complex, noisy input-output system. The function of this variability, in part, is to detect how the environment responds to such actions. World-learning denotes the biological process by which value is assigned to environmental stimuli. Self-learning is the biological process which assigns value to a specific action or movement. In an operant learning situation using visual stimuli for flies, world-learning inhibits self-learning via a prominent neuropil region, the mushroom-bodies. Only extended training can overcome this inhibition and lead to habit formation by engaging the self-learning mechanism. Self-learning transforms spontaneous, flexible actions into stereotyped, habitual responses.     

Multiple Defects in the Activity of Adenylate Cyclase from the Drosophila Memory Mutant Rutabaga

Adenylate cyclase in homogenates of Drosophila melanogaster is heterogeneous with respect to its affinity toward MgATP and its subcellular distribution. Km values for MgATP range, under similar assay conditions, from approximately 10(-5) M to approximately 10(-3) M, depending on the body region and on the subcellular localization of the enzyme. The majority of the enzyme in whole-body preparations is particulate, but various body regions differ in the relative proportion of the soluble enzyme. The memory mutant rutabaga lacks up to 35% of the total particulate activity. Even ligands that stimulate directly the catalytic subunit are incapable of bringing the activity of the mutant's enzyme to normal levels. The defect is differentially pronounced in various body parts and is associated with an altered responsiveness of the enzyme to Mg2+, to Ca2+, and to forskolin. It is suggested that rutabaga is lesioned in a subpopulation, or a functional state, of adenylate cyclase, which may play a role in memory formation.     

大壁虎与嗅觉相关的学习记忆

壁虎科动物鼻腔较大,化学感觉系统发达,类似于对化学信息敏感的舌端游离的蜥蜴目动物（Malan,1946),并且嗅黏膜面积很大,感觉器神经元多,嗅神经系统十分完善（Gabe and Saint,1976).     

Effects of peptides on animal and human behavior: a review of studies published in the first twenty years of the journal Peptides.

This review catalogs effects of peptides on various aspects of animal and human behavior as published in the journal Peptides in its first twenty years. Topics covered include: activity levels, addiction behavior, ingestive behaviors, learning and memory-based behaviors, nociceptive behaviors, social and sexual behavior, and stereotyped and other behaviors. There are separate tables for these behaviors and a short introduction for each section.     

Effects of peptides on animal and human behavior: a review of studies published in the first twenty years of the journal Peptides

This review catalogs effects of peptides on various aspects of animal and human behavior as published in the journal Peptides in its first twenty years. Topics covered include: activity levels, addiction behavior, ingestive behaviors, learning and memory-based behaviors, nociceptive behaviors, social and sexual behavior, and stereotyped and other behaviors. There are separate tables for these behaviors and a short introduction for each section.     

中医理论对指导提高学习能力及记忆力的讨论

中医理论认为,脑功能的正常发挥与五脏有着极其密切的关系。因此学习记忆力下降的病因病机可以概括为五脏失调,五志失和,神机失用。五脏中一个或多个发生病理改变,都可能影响到脑的生理功能从而引起记忆力下降。因此中医可从通过调节五脏,使五脏调和,即可达到提高记忆力的目的。     

苯甲醛对果蝇视觉联想记忆的阻断

采用飞行模拟系统,以视觉模式为线索、热惩罚为负强化因子,对于在不同发育时期经受苯甲醛处理过的果蝇的视觉飞行定向条件化进行了检验。苯甲醛气味分别作用于果蝇幼虫和成虫阶段,将阻断果蝇成虫建立视觉联想记忆的能力;雌性果蝇在处女期对苯甲醛气味的接触,会阻断其子代建立视觉联想记忆,这种视觉联想记忆的能力可以通过对其子代连续３代的正常饲养而逐渐得到恢复。     

Evidence for male-driven evolution in Drosophila

In several vertebrate taxa studied to date, mutation rates arehigher in males than females (male-driven evolution). The male-to-femalemutation rate () can be estimated by contrasting DNA divergencedata at X-linked, Y-linked, and autosomal loci. Previous studiesin Drosophila, comparing X-linked and autosomal divergence,have found no evidence for male-driven evolution in this genus.Here, I compare levels of nucleotide divergence between homologousX- and Y-linked loci in Drosophila miranda. Using divergenceat both synonymous sites and at short introns, I estimate tobe approximately 2. This study thus provides the first evidencefor male-biased mutation rates outside vertebrates, supportingthe view that DNA sequence evolution is male driven in a widevariety of taxa.     

Failure of posttrial administration of vasopressin analogue (DDAVP) to influence memory in healthy, young, male volunteers

The effects of intranasal treatment with DDAVP on healthy, male volunteers was assessed. Subjects were asked to learn prose passages and then were given either 60 μg of DDAVP or saline in a double-blind procedure. Subjects were then asked to recall the passages after a 24-h delay. Treatment had no effect on recall of passages. This suggests that treatment with vasopressin affects acquisition rather than consolidation of newly learned information.     

丙泊酚对认知的损伤及成瘾性研究进展

作为一种临床上常用的静脉麻醉药,丙泊酚主要用于诱导或维持全身麻醉,近年来随着临床实践及实验室研究发现,除了麻醉作用外,丙泊酚还有许多其他非麻醉效应。如在给药期间可导致认知功能的损伤,其机制可能涉及增强抑制性神经元的活性、抑制兴奋性神经元的活性、抑制某些神经递质如一氧化氮的产生等影响记忆的形成;同时该药一经临床使用,就有报道指出其可能存在潜在的成瘾性,而后续多数研究均提示其能够诱导奖赏效应的产生从而导致其成瘾及滥用。为更好的推动对丙泊酚认知功能损伤的机制及保护措施的研究、以及其成瘾机制及戒断方法的研究,本文就近年丙泊酚对认知功能损伤作用及潜在成瘾性的研究进展作一综述。     

Contextual and Cued Fear Conditioning Test Using a Video Analyzing System in Mice

The contextual and cued fear conditioning test is one of the behavioral tests that assesses the ability of mice to learn and remember an association between environmental cues and aversive experiences. In this test, mice are placed into a conditioning chamber and are given parings of a conditioned stimulus (an auditory cue) and an aversive unconditioned stimulus (an electric footshock). After a delay time, the mice are exposed to the same conditioning chamber and a differently shaped chamber with presentation of the auditory cue. Freezing behavior during the test is measured as an index of fear memory. To analyze the behavior automatically, we have developed a video analyzing system using the ImageFZ application software program, which is available as a free download at http://www.mouse-phenotype.org/. Here, to show the details of our protocol, we demonstrate our procedure for the contextual and cued fear conditioning test in C57BL/6J mice using the ImageFZ system. In addition, we validated our protocol and the video analyzing system performance by comparing freezing time measured by the ImageFZ system or a photobeam-based computer measurement system with that scored by a human observer. As shown in our representative results, the data obtained by ImageFZ were similar to those analyzed by a human observer, indicating that the behavioral analysis using the ImageFZ system is highly reliable. The present movie article provides detailed information regarding the test procedures and will promote understanding of the experimental situation.     

Study Motor Skill Learning by Single-pellet Reaching Tasks in Mice

Reaching for and retrieving objects require precise and coordinated motor movements in the forelimb. When mice are repeatedly trained to grasp and retrieve food rewards positioned at a specific location, their motor performance (defined as accuracy and speed) improves progressively over time, and plateaus after persistent training. Once such reaching skill is mastered, its further maintenance does not require constant practice. Here we introduce a single-pellet reaching task to study the acquisition and maintenance of skilled forelimb movements in mice. In this video, we first describe the behaviors of mice that are commonly encountered in this learning and memory paradigm, and then discuss how to categorize these behaviors and quantify the observed results. Combined with mouse genetics, this paradigm can be utilized as a behavioral platform to explore the anatomical underpinnings, physiological properties, and molecular mechanisms of learning and memory.     

Free-living pathogens: life-history constraints and strain competition

Many pathogen life histories include a free-living stage, often with anatomical and physiological adaptations promoting persistence outside of host tissues. More durable particles presumably require that the pathogen metabolize more resources per particle. Therefore, we hypothesize functional dependencies, pleiotropic constraints, between the rate at which free-living particles decay outside of host tissues and other pathogen traits, including virulence, the probability of infecting a host upon contact, and pathogen reproduction within host tissues. Assuming that pathogen strains compete for hosts preemptively, we find patterns in trait dependencies predicting whether or not strain competition favors a highly persistent free-living stage.     

A role for Melanin-Concentrating Hormone in learning and memory

The neurobiological substrate of learning process and persistent memory storage involves multiple brain areas. The neocortex and hippocampal formation are known as processing and storage sites for explicit memory, whereas the striatum, amygdala, neocortex and cerebellum support implicit memory. Synaptic plasticity, long-term changes in synaptic transmission efficacy and transient recruitment of intracellular signaling pathways in these brain areas have been proposed as possible mechanisms underlying short- and long-term memory retention. In addition to the classical neurotransmitters (glutamate, GABA), experimental evidence supports a role for neuropeptides in modulating memory processes. This review focuses on the role of the Melanin-Concentrating Hormone (MCH) and receptors on memory formation in animal studies. Possible mechanisms may involve direct MCH modulation of neural circuit activity that support memory storage and cognitive functions, as well as indirect effect on arousal.