Operant behavior changes norepinephrine metabolism in rat brain

Rats performing a lever-pressing response for water reward in an operant situation, when compared with control groups, showed an increase in brain norepinephrine metabolism. One control group included rats which were handled and deprived of water in the same way as the experimental group but were not trained to perform the operant task. We conclude that performance in an operant situation affects norepinephrine metabolism.     

Selective attention from voluntary control of neurons in prefrontal cortex

Animals can learn to voluntarily control neuronal activity within various brain areas through operant conditioning, but the relevance of that control to cognitive functions is unknown. We found that rhesus monkeys can control the activity of neurons within the frontal eye field (FEF), an oculomotor area of the prefrontal cortex. However, operantly driven FEF activity was primarily associated with selective visual attention, and not oculomotor preparation. Attentional effects were untrained and were observed both behaviorally and neurophysiologically. Furthermore, selective attention correlated with voluntary, but not spontaneous, fluctuations in FEF activity. Our results reveal a specific association of voluntarily driven neuronal activity with "top-down" attention and suggest a basis for the use of neurofeedback training to treat disorders of attention.     

Circadian rhythm of brain self-stimulation behavior

Under constant conditions of light, sound, temperature, and humidity, rats exhibited circadian rhythmicity in rate of bar-pressing with hypothalamic and septal reinforcing brain stimulation. Variations in reinforcer magnitude aflected absolute levels of operant response emission but not the frequency of the circadian rhythm. In long sessions, the time of peak responding deviated systematically from a strict 24-hour period. Such data show marked similarity to free-running rhythms of motor activity.     

一类混沌系统的Hopf分岔控制

针对带参数的混沌系统,运用Routh-Hurwitz判据及Hopf分岔理论研究系统存在的动力学行为,设计状态反馈控制器对系统进行Hopf分岔控制。分析系统参数及控制参数分别对系统稳定性与Hopf分岔类型的影响,得到了系统稳定及不发生Hopf分岔的系统参数条件。研究结果表明：控制器中的线性控制部分及非线性控制部分均能改变系统的分岔行为,使系统渐近稳定。数值仿真证明控制器设计的有效性。     

Amphetamine: differentiation by d and l isomers of behavior involving brain norepinephrine or dopamine

d-Amphetamine is markedly more potent an inhibitor of catecholamine uptake by norepinephrine neurons in the brain than is 1-amphetamine, whereas the two isomers are equally active in inhibiting catecholamine uptake by the dopamine neurons of the corpus striatum. In behavioral studies, d-amphetamine is ten times as potent as 1-amphetamine in enhancing locomotor activity, while it is only twice as potent in eliciting a compulsive gnawing syndrome. This suggests that the locomotor stimulation induced by amphetamine involves central norepinephrine, while dopamine neurons play an important role in the induced compulsive gnawing behavior. Assessment of differential actions of d- and 1-amphetamine may be an efficient method to differentiate behaviors involving norepinephrine or dopamine in the brain.     

Serotonin transporter genetic variation and the response of the human amygdala

A functional polymorphism in the promoter region of the human serotonin transporter gene (SLC6A4) has been associated with several dimensions of neuroticism and psychopathology, especially anxiety traits, but the predictive value of this genotype against these complex behaviors has been inconsistent. Serotonin [5- hydroxytryptamine, (5-HT)] function influences normal fear as well as pathological anxiety, behaviors critically dependent on the amygdala in animal models and in clinical studies. We now report that individuals with one or two copies of the short allele of the serotonin transporter (5-HTT) promoter polymorphism, which has been associated with reduced 5-HTT expression and function and increased fear and anxiety-related behaviors, exhibit greater amygdala neuronal activity, as assessed by BOLD functional magnetic resonance imaging, in response to fearful stimuli compared with individuals homozygous for the long allele. These results demonstrate genetically driven variation in the response of brain regions underlying human emotional behavior and suggest that differential excitability of the amygdala to emotional stimuli may contribute to the increased fear and anxiety typically associated with the short SLC6A4 allele.     

基于遗传算法的多移动机器人编队行为控制

在对多移动机器人行为分解的基础上,采用基于基本行为旋转的合成策略,实现了对机器人移动过程中的编队控制,并利用遗传算法对行为控制参数进行了优化。仿真结果表明,该方法是简单有效的。     

Recovery of feeding and drinking by rats after intraventricular 6-hydroxydopamine or lateral hypothalamic lesions

Rats given intraventricular injections of 6-hydroxydopamine after pretreatment with pargyline become aphagic and adipsic, and show severe loss of brain catecholamines. Like rats with lateral hypothalamic lesions, these animals gradually recover ingestive behaviors, although catecholamine depletions are permanent. Both groups decrease food and water intakes markedly after the administration of alpha-methyltyrosine, at doses that do not affect the ingestive behaviors of control rats. Thus, both the loss and recovery of feeding and drinking behaviors may involve central catecholamine-containing neurons.     

Intersubject synchronization of cortical activity during natural vision

To what extent do all brains work alike during natural conditions? We explored this question by letting five subjects freely view half an hour of a popular movie while undergoing functional brain imaging. Applying an unbiased analysis in which spatiotemporal activity patterns in one brain were used to "model" activity in another brain, we found a striking level of voxel-by-voxel synchronization between individuals, not only in primary and secondary visual and auditory areas but also in association cortices. The results reveal a surprising tendency of individual brains to "tick collectively" during natural vision. The intersubject synchronization consisted of a widespread cortical activation pattern correlated with emotionally arousing scenes and regionally selective components. The characteristics of these activations were revealed with the use of an open-ended "reverse-correlation" approach, which inverts the conventional analysis by letting the brain signals themselves "pick up" the optimal stimuli for each specialized cortical area.     

G-CSF对脑挫伤大鼠血清及脑组织中NO、MDA和SOD含量的影响

目的观察粒细胞集落刺激因子（G-CSF）对脑挫伤大鼠血清及脑组织中一氧化氮（NO）、丙二醛（MDA）和超氧化物歧化酶（SOD）含量的影响,探讨G-CSF在治疗脑挫伤中的作用.方法将大鼠随机分为治疗组、对照组和正常组,采用自由落体法致SD大鼠脑挫伤动物模型,正常组不致伤.治疗组脑挫伤2h后开始应用G-CSF（浓度为2mg/L）一次性皮下注射50μg/kg治疗.对照组和正常组皮下注射等量生理盐水.给药结束后24h检测治疗组、对照组及正常组大鼠血清及脑组织中NO、MDA和SOD的含量.结果脑挫伤后,对照组大鼠血清及脑组织中NO和MDA含量明显高于正常组,SOD的活性明显低于正常组.治疗组大鼠血清及脑组织中NO和MDA含量明显低于对照组,SOD的活性明显高于对照组.结论G-CSF能有效地提高脑挫伤大鼠血清及脑组织中SOD的活性,降低NO和MDA含量,保护脑组织,改善脑水肿,从而起到了一定的治疗作用.     

大矢跨比车行索道桥结构的可行性

根据索道桥的通行标准,采用几何非线性有限元方法,借助ANSYS软件分析大矢跨比车行索道桥静力特性,对比并考察了其施工可行性与结构经济性.结果表明大矢跨比索道桥的所有结构行为参数都达到常规索道桥的技术要求;所有构件的安装具有可施工性;结构的经济性优势显著,该结构可行性好.     

黄唇蜾蠃蜂蜂毒的毒性特征研究

通过分析黄唇蜾蠃蜂蜂毒中的蛋白质组分,发现SDS-PAGE可以分离出5条主要的蛋白质带.酶活力分析显示,黄唇蜾蠃蜂蜂毒和已研究过的其他胡蜂蜂毒一样,也具有透明质酸酶和磷脂酶A的活性,但蜂毒中没有检测到酯酶、磷脂酶C和酚氧化酶活性,也不含有酚氧化酶抑制因子.由此推测,黄唇蜾蠃蜂的蜂毒仅具有较弱的过敏活性.利用寄主斜纹夜蛾幼虫进行生理学活性分析证实,体腔注射黄唇蜾蠃蜂蜂毒不能引起寄主昆虫的麻痹反应,但脑部注射一个毒腺当量的蜂毒就会引起所有受试个体产生麻痹反应,但用胰蛋白酶处理后,蜂毒即失去麻痹活性.表明:黄唇蜾蠃蜂蜂毒的麻痹活性依赖于其蛋白质组分,而活性组分的作用靶标位于寄主昆虫的中枢神经系统.     

Human muscle phosphoglycerate mutase deficiency: newly discovered metabolic myopathy

Muscle phosphoglycerate mutase activity was decreased (5.7 percent of the lowest control value) in a 52-year-old man with intolerance for strenuous exercise and recurrent pigmenturia since adolescence. All of the other enzymes of glycolysis had normal activities, and glycogen concentration was normal. Electrophoretic, heat lability, and mercury inhibition studies showed that the small residual activity in the patient's muscle was represented by the brain (BB) isoenzyme of phosphoglycerate mutase, suggesting a genetic defect of the M subunit which predominates in normal muscle. The prevalence of the BB isoenzyme in other tissues, including muscle culture, may explain why symptoms were confined to muscle.     

Operant control of occipital theta rhythm affects performance in a radar monitoring task

Detection efficiency of human observers deteriorates rapidly in monotonous monitoring tasks; this effect (the vigilance decrement) has been associated with increased theta band activity in the electroencephalogram. Suppression of theta activity by operant methods enhances monitoring efficiency, whereas theta augmentation further degrades task performance. These results demonstrate a lawful relationship between operantly regulated cortical activity and behavior in man.     

Signaled reinforcing brain stimulation facilitates operant behavior under schedules of intermittent reinforcement

When single, rewarding brain stimulations were mnade predictable by preceding them with a brief warning signal, operant behavior was established and maintained under fixed ratio 200, variable ratio 30, fixed interval 3-minute, variable interval 2-minute, and differential reinforcement of low rate 20-second schedules of intermittent reinforcement. When the warning signal was removed, overall response rate declined in all but the fixed ratio schedules and then returned to the previous rate when the signal was reinstated.     

Operant reward learning in Aplysia: neuronal correlates and mechanisms

Operant conditioning is a form of associative learning through which an animal learns about the consequences of its behavior. Here, we report an appetitive operant conditioning procedure in Aplysia that induces long-term memory. Biophysical changes that accompanied the memory were found in an identified neuron (cell B51) that is considered critical for the expression of behavior that was rewarded. Similar cellular changes in B51 were produced by contingent reinforcement of B51 with dopamine in a single-cell analog of the operant procedure. These findings allow for the detailed analysis of the cellular and molecular processes underlying operant conditioning.     

Interaction between purine and benzodiazepine: Inosine reverses diazepam-induced stimulation of mouse exploratory behavior

Inosine, 2-deoxyinosine, and 2-deoxyguanosine completely reversed the increase in exploratory activity elicited in mice by diazepam. The inhibition of exploratory behavior by purines occurred at doses that when given alone have no effect on exploratory behavior. 7-Methylinosine, which does not bind to the brain benzodiazepine binding site in vitro, had no effect on the diazepam-induced increase in exploratory behavior. Behavioral effects produced by various combinations of inosine and diazepam indicate that the interaction between purine and benzodiazepine is antagonistic and support the hypothesis that the naturally occurring purines function in anxiety-related behaviors that respond to benzodiazepine treatment.     

Procedure for Studying Olfactory Discrimination in Pigeons

A discrimination, based on olfactory stimuli, was established in two pigeons by an operant conditioning procedure. Results from control sessions demonstrate that the discrimination can be attributed only to the presence or absence of olfactory stimuli.     

High-speed imaging reveals neurophysiological links to behavior in an animal model of depression

The hippocampus is one of several brain areas thought to play a central role in affective behaviors, but the underlying local network dynamics are not understood. We used quantitative voltage-sensitive dye imaging to probe hippocampal dynamics with millisecond resolution in brain slices after bidirectional modulation of affective state in rat models of depression. We found that a simple measure of real-time activity-stimulus-evoked percolation of activity through the dentate gyrus relative to the hippocampal output subfield-accounted for induced changes in animal behavior independent of the underlying mechanism of action of the treatments. Our results define a circuit-level neurophysiological endophenotype for affective behavior and suggest an approach to understanding circuit-level substrates underlying psychiatric disease symptoms.     

Sleep after exercise

After moderate treadmill exercise, marked decreases in operant responding and in latency to onset of behavioral sleep occurs in cats. The sleep produced is characterized by enhancement of synchronized electroencephalographic activity with suppression of the desynchronized phase. The result is consistent with the theory that a function of synchronized sleep is to facilitate recovery from fatigue.