Exploratory Behavior: The tendency to explore or investigate a novel environment. It is considered a motivation not clearly distinguishable from curiosity.Behavior, Animal: The observable response an animal makes to any situation.Motor Activity: The physical activity of a human or an animal as a behavioral phenomenon.Psychology, Experimental: The branch of psychology which seeks to learn more about the fundamental causes of behavior by studying various psychologic phenomena in controlled experimental situations.Maze Learning: Learning the correct route through a maze to obtain reinforcement. It is used for human or animal populations. (Thesaurus of Psychological Index Terms, 6th ed)Illness Behavior: Coordinate set of non-specific behavioral responses to non-psychiatric illness. These may include loss of APPETITE or LIBIDO; disinterest in ACTIVITIES OF DAILY LIVING; or withdrawal from social interaction.Grooming: An animal's cleaning and caring for the body surface. This includes preening, the cleaning and oiling of feathers with the bill or of hair with the tongue.Hyperkinesis: Excessive movement of muscles of the body as a whole, which may be associated with organic or psychological disorders.Habituation, Psychophysiologic: The disappearance of responsiveness to a repeated stimulation. It does not include drug habituation.Social Behavior: Any behavior caused by or affecting another individual, usually of the same species.Anxiety: Feeling or emotion of dread, apprehension, and impending disaster but not disabling as with ANXIETY DISORDERS.Locomotion: Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.Spatial Behavior: Reactions of an individual or groups of individuals with relation to the immediate surrounding area including the animate or inanimate objects within that area.Avoidance Learning: A response to a cue that is instrumental in avoiding a noxious experience.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Biogenic Amines: A group of naturally occurring amines derived by enzymatic decarboxylation of the natural amino acids. Many have powerful physiological effects (e.g., histamine, serotonin, epinephrine, tyramine). Those derived from aromatic amino acids, and also their synthetic analogs (e.g., amphetamine), are of use in pharmacology.Corticosterone: An adrenocortical steroid that has modest but significant activities as a mineralocorticoid and a glucocorticoid. (From Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1437)Restraint, Physical: Use of a device for the purpose of controlling movement of all or part of the body. Splinting and casting are FRACTURE FIXATION.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Feeding Behavior: Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Fear: The affective response to an actual current external danger which subsides with the elimination of the threatening condition.Hippocampus: A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.Memory: Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.Stress, Physiological: The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Mice, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.Animals, Newborn: Refers to animals in the period of time just after birth.Health Behavior: Behaviors expressed by individuals to protect, maintain or promote their health status. For example, proper diet, and appropriate exercise are activities perceived to influence health status. Life style is closely associated with health behavior and factors influencing life style are socioeconomic, educational, and cultural.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Stress, Psychological: Stress wherein emotional factors predominate.Mice, Inbred C57BLTime Factors: Elements of limited time intervals, contributing to particular results or situations.Space Perception: The awareness of the spatial properties of objects; includes physical space.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Behavior: The observable response of a man or animal to a situation.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Sexual Behavior: Sexual activities of humans.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Sexual Behavior, Animal: Sexual activities of animals.Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Child Behavior: Any observable response or action of a child from 24 months through 12 years of age. For neonates or children younger than 24 months, INFANT BEHAVIOR is available.Adolescent Behavior: Any observable response or action of an adolescent.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Child Behavior Disorders: Disturbances considered to be pathological based on age and stage appropriateness, e.g., conduct disturbances and anaclitic depression. This concept does not include psychoneuroses, psychoses, or personality disorders with fixed patterns.Maternal Behavior: The behavior patterns associated with or characteristic of a mother.Behavior Therapy: The application of modern theories of learning and conditioning in the treatment of behavior disorders.Stereotyped Behavior: Relatively invariant mode of behavior elicited or determined by a particular situation; may be verbal, postural, or expressive.
Curiosity: Curiosity (from Latin curiosus "careful, diligent, curious," akin to cura "care") is a quality related to inquisitive thinking such as exploration, investigation, and learning, evident by observation in human and animal species. Curiosity is heavily associated with all aspects of human development, in which derives the process of learning and desire to acquire knowledge and skill.Loftus, North YorkshireLearning Plan: A Learning Plan is a document (possibly an interactive or on-line document) that is used to plan learning, usually over an extended period of time.Sickness behavior: [Ancher 001.jpg|thumb|350px|right|Ancher, Michael], "The Sick Girl", 1882, [[Statens Museum for Kunst.Charles Ottley Groom NapierHyperkinesiaSensitization: Sensitization is a non-associative learning process in which repeated administrations of a stimulus results in the progressive amplification of a response. Sensitization often is characterized by an enhancement of response to a whole class of stimuli in addition to the one that is repeated.Genetics of social behavior: The genetics of social behavior is an area of research that attempts to address the question of the role that genes play in modulating the neural circuits in the brain which influence social behavior. Model genetic species, such as D.Hypervigilance: Hypervigilance is an enhanced state of sensory sensitivity accompanied by an exaggerated intensity of behaviors whose purpose is to detect threats. Hypervigilance is also accompanied by a state of increased anxiety which can cause exhaustion.Walker (BEAM): In BEAM robotics, a walker is a walking machine that has a driven mode of locomotion by intermittent ground-contacting legs. They usually possess 1 to 12 (generally, three or less) motors.Avoidance reactionBiogenic amine: A biogenic amine is a biogenic substance with one or more amine groups. They are basic nitrogenous compounds formed mainly by decarboxylation of amino acids or by amination and transamination of aldehydes and ketones.CorticosteronePhysical restraintFear conditioning: Fear conditioning is a behavioral paradigm in which organisms learn to predict aversive events. It is a form of learning in which an aversive stimulus (e.Place cellExplicit memory: Explicit memory is the conscious, intentional recollection of previous experiences and information. People use explicit memory throughout the day, such as remembering the time of an appointment or recollecting an event from years ago.Gross pathology: Gross pathology refers to macroscopic manifestations of disease in organs, tissues, and body cavities. The term is commonly used by anatomical pathologists to refer to diagnostically useful findings made during the gross examination portion of surgical specimen processing or an autopsy.Evolution in Variable EnvironmentBehavior: Behavior or behaviour (see spelling differences) is the range of actions and [made by individuals, organism]s, [[systems, or artificial entities in conjunction with themselves or their environment, which includes the other systems or organisms around as well as the (inanimate) physical environment. It is the response of the system or organism to various stimuli or inputs, whether [or external], [[conscious or subconscious, overt or covert, and voluntary or involuntary.Stressor: A stressor is a chemical or biological agent, environmental condition, external stimulus or an event that causes stress to an organism.Temporal analysis of products: Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studyingHSD2 neurons: HSD2 neurons are a small group of neurons in the brainstem which are uniquely sensitive to the mineralocorticosteroid hormone aldosterone, through expression of HSD11B2. They are located within the caudal medulla oblongata, in the nucleus of the solitary tract (NTS).Concentration effect: In the study of inhaled anesthetics, the concentration effect is the increase in the rate that the Fa(alveolar concentration)/Fi(inspired concentration) ratio rises as the alveolar concentration of that gas is increased. In simple terms, the higher the concentration of gas administered, the faster the alveolar concentration of that gas approaches the inspired concentration.Sexual motivation and hormones: Sexual motivation is influenced by hormones such as testosterone, estrogen, progesterone, oxytocin, and vasopressin. In most mammalian species, sex hormones control the ability to engage in sexual behaviours.
(1/1874) Gabapentin suppresses ectopic nerve discharges and reverses allodynia in neuropathic rats.
Repetitive ectopic discharges from injured afferent nerves play an important role in initiation and maintenance of neuropathic pain. Gabapentin is effective for treatment of neuropathic pain but the sites and mechanisms of its antinociceptive actions remain uncertain. In the present study, we tested a hypothesis that therapeutic doses of gabapentin suppress ectopic afferent discharge activity generated from injured peripheral nerves. Mechanical allodynia, induced by partial ligation of the sciatic nerve in rats, was determined by application of von Frey filaments to the hindpaw. Single-unit afferent nerve activity was recorded proximal to the ligated sciatic nerve site. Intravenous gabapentin, in a range of 30 to 90 mg/kg, significantly attenuated allodynia in nerve-injured rats. Furthermore, gabapentin, in the same therapeutic dose range, dose-dependently inhibited the ectopic discharge activity of 15 injured sciatic afferent nerve fibers through an action on impulse generation. However, the conduction velocity and responses of 12 normal afferent fibers to mechanical stimulation were not affected by gabapentin. Therefore, this study provides electrophysiological evidence that gabapentin is capable of suppressing the ectopic discharge activity from injured peripheral nerves. This action may contribute, at least in part, to the antiallodynic effect of gabapentin on neuropathic pain. (+info)
(2/1874) Cladistic association analysis of Y chromosome effects on alcohol dependence and related personality traits.
Association between Y chromosome haplotype variation and alcohol dependence and related personality traits was investigated in a large sample of psychiatrically diagnosed Finnish males. Haplotypes were constructed for 359 individuals using alleles at eight loci (seven microsatellite loci and a nucleotide substitution in the DYZ3 alphoid satellite locus). A cladogram linking the 102 observed haplotype configurations was constructed by using parsimony with a single-step mutation model. Then, a series of contingency tables nested according to the cladogram hierarchy were used to test for association between Y haplotype and alcohol dependence. Finally, using only alcohol-dependent subjects, we tested for association between Y haplotype and personality variables postulated to define subtypes of alcoholism-antisocial personality disorder, novelty seeking, harm avoidance, and reward dependence. Significant association with alcohol dependence was observed at three Y haplotype clades, with significance levels of P = 0.002, P = 0.020, and P = 0.010. Within alcohol-dependent subjects, no relationship was revealed between Y haplotype and antisocial personality disorder, novelty seeking, harm avoidance, or reward dependence. These results demonstrate, by using a fully objective association design, that differences among Y chromosomes contribute to variation in vulnerability to alcohol dependence. However, they do not demonstrate an association between Y haplotype and the personality variables thought to underlie the subtypes of alcoholism. (+info)
(3/1874) Increased exploratory activity and altered response to LSD in mice lacking the 5-HT(5A) receptor.
In order to determine the distribution and function of the 5-HT5A serotonin receptor subtype, we generated knockout mice lacking the 5-HT5A gene. Comparative autoradiography studies of brains of wild-type (wt) and 5-HT5A knockout (5A-KO) mice revealed the existence of binding sites with high affinity for [125I]LSD that correspond to 5-HT5A receptors and that are concentrated in the olfactory bulb, neocortex, and medial habenula. When exposed to novel environments, the 5A-KO mice displayed increased exploratory activity but no change in anxiety-related behaviors. In addition, the stimulatory effect of LSD on exploratory activity was attenuated in 5A-KO mice. These results suggest that 5-HT5A receptors modulate the activity of neural circuits involved specifically in exploratory behavior and suggest that some of the psychotropic effects of LSD may be mediated by 5-HT5A receptors. (+info)
(4/1874) Characterization of the electrophysiological and pharmacological effects of 4-iodo-2,6-diisopropylphenol, a propofol analogue devoid of sedative-anaesthetic properties.
1. Several derivatives and analogues of the general anaesthetic 2,6-diisopropylphenol (propofol) have been recently synthesised with the aim of exploring the structure-activity relationships. 2. In the present study, the effects of one such compound, 4-iodo-2,6-diisopropylphenol (4-I-Pro), on gamma-aminobutyric acid type A (GABA(A)) receptors in vitro were compared with its in vivo effects in rodents. Human GABA(A) receptors were expressed in Xenopus oocytes, and the actions of 4-I-Pro on receptor function were compared with those of propofol by two-electrode voltage-clamp recording. 3. Similar to propofol, 4-I-Pro directly activated Cl- currents in the absence of GABA at all combinations of receptor subunits tested. However, the efficacy of 4-I-Pro in inducing direct activation of alpha1beta2gamma2S receptors was markedly less than that of propofol. 4. Similarly to propofol, 4-I-Pro potentiated in a concentration-dependent manner GABA-evoked Cl- currents measured at different GABA(A) receptor constructs. 5. As expected, intraperitoneal injection of propofol induced sedation, ataxia, and loss of the righting reflex in rats. In contrast, administration of 4-I-Pro failed to produce any of these behavioural effects. 6. Administration of 4-I-Pro to rats reduced in a dose-dependent manner the incidence of tonic-clonic seizures induced by pentylenetetrazol and induced an anticonflict effect as measured in the Vogel test. 7. Microdialysis revealed that, like propofol, administration of 4-I-Pro reduced acetylcholine release in the hippocampus of freely moving rats. 8. These results demonstrate that para-substitution of the phenol ring of propofol with iodine yields a compound that exhibits anticonvulsant and anticonflict effects, but is devoid of sedative-hypnotic and anaesthetic properties. Thus, 4-I-Pro possesses pharmacological characteristics more similar to anxiolytic and anticonvulsant drugs than to general anaesthetics. (+info)
(5/1874) T-lymphocyte activation increases hypothalamic and amygdaloid expression of CRH mRNA and emotional reactivity to novelty.
Stimulation of T-cells with staphylococcal enterotoxin B (SEB) significantly elevates interleukin-2 (IL-2) and contemporaneous activation of the hypothalamic-pituitary-adrenal (HPA) axis and c-fos in the paraventricular nucleus (PVN) of BALB/cByJ mice. Such neural signaling may promote cognitive and emotional adaptation before or during infectious illness. Because corticotropin-releasing hormone (CRH) is an anxiogenic neuropeptide that may mediate the stressor-like effects of immunological stimuli, we measured neuronal CRH mRNA alterations in mice challenged with SEB. Increased CRH mRNA levels were observed in the PVN and central nucleus of the amygdala (ceA) 4-6 hr after SEB administration. This was associated with plasma ACTH increases, which could be abrogated by the systemic administration of anti-CRH antiserum. Additional experiments did not support a role for IL-2 or prostaglandin synthesis in activating the HPA axis. Behavioral experiments testing for conditioned taste aversion did not confirm that SEB challenge promotes malaise. However, consistent with the notion that central CRH alterations induced by SEB may affect emotionality (e.g., fear), SEB challenge augmented appetitive neophobia in a context-dependent manner, being marked in a novel and stressful environment. It is hypothesized that immunological stimuli generate a cascade of events that solicit integrative neural processes involved in emotional behavior. As such, these data support the contention that affective illness may be influenced by immunological processes and the production of cytokines and are consistent with other evidence demonstrating that autoimmune reactivity is associated with enhanced emotionality. (+info)
(6/1874) Sensitization to the effects of tumor necrosis factor-alpha: neuroendocrine, central monoamine, and behavioral variations.
Consistent with the proposition that cytokines act as immunotransmitters between the immune system and the brain, systemic administration of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha; 1.0-4.0 microg) induced mild illness in CD-1 mice, increased plasma corticosterone concentrations, and altered central norepinephrine, dopamine, and serotonin turnover. The actions of TNF-alpha were subject to a time-dependent sensitization effect. After reexposure to a subeffective dose of the cytokine (1.0 microgram) 14-28 d after initial treatment, marked illness was evident (reduced consumption of a palatable substance and diminished activity and social exploration), coupled with an elevation of plasma corticosterone levels. In contrast, cytokine reexposure 1-7 d after initial treatment did not elicit illness, and at the 1 d interval the corticosterone response to the cytokine was reduced. The increase of norepinephrine release within the paraventricular nucleus of the hypothalamus, as reflected by elevated accumulation of 3-methoxy-4-hydroxyphenylglycol, was augmented at the longer reexposure intervals. In contrast, within the central amygdala and the prefrontal cortex TNF-alpha reexposure at the 1 d interval was associated with a pronounced sensitization-like effect, which was not apparent at longer intervals. Evidently, systemic TNF-alpha proactively influences the response to subsequent treatment; however, the nature of the effects (i.e., the behavioral, neuroendocrine, and central transmitter alterations) vary over time after initial cytokine treatment. It is suggested that the sensitization may have important repercussions with respect to cognitive effects of TNF-alpha and may also be relevant to analyses of the neuroprotective or neurodestructive actions of cytokines. (+info)
(7/1874) Dopamine D4 receptor gene: novelty or nonsense?
Although the role of genetics in personality has been studied extensively at a phenomenological level, only lately has the investigation of specific genes been performed. Recent reports suggest that DNA variants of the dopamine D4 receptor gene (DRD4) are associated with the personality trait of novelty seeking; however, others fail to replicate this finding. Such conflicting results suggest either a weak effect, an association only in certain populations, or a false-positive resulting from population stratification. We provide a critical analysis of genetic studies of DRD4 variants with novelty seeking, alcoholism, drug abuse, and attention deficit hyperactivity disorder. Evidence for the role of DRD4 in novelty seeking is inconclusive, with a number of methodological concerns. Use of more conservative statistical criteria for significance, employing gene haplotypes, as well as linkage disequilibrium studies, are recommended. The molecular biology of the D4 gene is also reviewed. (+info)
(8/1874) 5-HT1B receptor knock-out mice exhibit increased exploratory activity and enhanced spatial memory performance in the Morris water maze.
In an attempt to characterize the contribution of the 5-HT1B receptor to behavior, 5-HT1B knock-out (KO) mice were subjected to a battery of behavioral paradigms aimed at differentiating various components of cognitive and emotional behaviors. In an object exploration task, wild-type (WT) and 5-HT1B KO mice did not differ in locomotor activity. 5-HT1B KO mice, however, displayed lower thigmotaxis (an index of anxiety) associated with a higher level of object exploratory activity, but no genotype differences were observed in the elevated plus maze. 5-HT1B KO mice also displayed a lack of exploratory habituation. In the spatial version of the Morris water maze, 5-HT1B KO mice showed higher performances in acquisition and transfer test, which was not observed in the visual version of the task. No genotype differences were found in contextual fear conditioning, because both WT and 5-HT1B KO mice were able to remember the context where they had received the aversive stimulus. The deletion of the 5-HT1B receptor, associated with appropriate behavioral paradigms, thus allowed us to dissociate anxiety from response to novelty, and perseverative behavior (lack of habituation) from adaptive behavioral inhibition underlying cognitive flexibility (transfer stage in the water maze). The deletion of the 5-HT1B receptor did not result in significant developmental plasticities for other major 5-HT receptor types but may have influenced other neurotransmission systems. The 5-HT1B receptor may be a key target for serotonin in the modulation of cognitive behavior, particularly in situations involving a high cognitive demand. (+info)