Anticipation, Genetic: The apparent tendency of certain diseases to appear at earlier AGE OF ONSET and with increasing severity in successive generations. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Anticipation, Psychological: The ability to foresee what is likely to happen on the basis of past experience. It is largely a frontal lobe function.Reward: An object or a situation that can serve to reinforce a response, to satisfy a motive, or to afford pleasure.ArchivesIntuition: Knowing or understanding without conscious use of reasoning. (Thesaurus of ERIC Descriptors, 1994)Cues: Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond.Performance Anxiety: Anxiety related to the execution of a task. (Campbell's Psychiatric Dictionary, 9th ed.)Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Set (Psychology): Readiness to think or respond in a predetermined way when confronted with a problem or stimulus situation.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Age of Onset: The age, developmental stage, or period of life at which a disease or the initial symptoms or manifestations of a disease appear in an individual.Motivation: Those factors which cause an organism to behave or act in either a goal-seeking or satisfying manner. They may be influenced by physiological drives or by external stimuli.Pain Perception: The process by which PAIN is recognized and interpreted by the brain.Reaction Time: The time from the onset of a stimulus until a response is observed.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Gyrus Cinguli: One of the convolutions on the medial surface of the CEREBRAL HEMISPHERES. It surrounds the rostral part of the brain and CORPUS CALLOSUM and forms part of the LIMBIC SYSTEM.Desulfovibrio desulfuricans: The type species of gram-negative, anaerobic bacteria of the genus DESULFOVIBRIO. It is found in FRESHWATER; SOIL, and in marine or brackish water.Psychophysiology: The study of the physiological basis of human and animal behavior.Spinocerebellar Degenerations: A heterogenous group of degenerative syndromes marked by progressive cerebellar dysfunction either in isolation or combined with other neurologic manifestations. Sporadic and inherited subtypes occur. Inheritance patterns include autosomal dominant, autosomal recessive, and X-linked.Arousal: Cortical vigilance or readiness of tone, presumed to be in response to sensory stimulation via the reticular activating system.Emotions: Those affective states which can be experienced and have arousing and motivational properties.Trinucleotide Repeats: Microsatellite repeats consisting of three nucleotides dispersed in the euchromatic arms of chromosomes.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Feeding Behavior: Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.Telomere Shortening: The loss of some TELOMERE sequence during DNA REPLICATION of the first several base pairs of a linear DNA molecule; or from DNA DAMAGE. Cells have various mechanisms to restore length (TELOMERE HOMEOSTASIS.) Telomere shortening is involved in the progression of CELL AGING.Carnosine: A naturally occurring dipeptide neuropeptide found in muscles.Galvanic Skin Response: A change in electrical resistance of the skin, occurring in emotion and in certain other conditions.Functional Neuroimaging: Methods for visualizing REGIONAL BLOOD FLOW, metabolic, electrical, or other physiological activities in the CENTRAL NERVOUS SYSTEM using various imaging modalities.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Contingent Negative Variation: A negative shift of the cortical electrical potentials that increases over time. It is associated with an anticipated response to an expected stimulus and is an electrical event indicative of a state of readiness or expectancy.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Gambling: An activity distinguished primarily by an element of risk in trying to obtain a desired goal, e.g., playing a game of chance for money.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.Endothelium, Corneal: Single layer of large flattened cells covering the surface of the cornea.Respite Care: Patient care provided in the home or institution intermittently in order to provide temporary relief to the family home care giver.Cytotoxins: Substances that are toxic to cells; they may be involved in immunity or may be contained in venoms. These are distinguished from CYTOSTATIC AGENTS in degree of effect. Some of them are used as CYTOTOXIC ANTIBIOTICS. The mechanism of action of many of these are as ALKYLATING AGENTS or MITOSIS MODULATORS.Myotonic Dystrophy: Neuromuscular disorder characterized by PROGRESSIVE MUSCULAR ATROPHY; MYOTONIA, and various multisystem atrophies. Mild INTELLECTUAL DISABILITY may also occur. Abnormal TRINUCLEOTIDE REPEAT EXPANSION in the 3' UNTRANSLATED REGIONS of DMPK PROTEIN gene is associated with Myotonic Dystrophy 1. DNA REPEAT EXPANSION of zinc finger protein-9 gene intron is associated with Myotonic Dystrophy 2.Basal Ganglia: Large subcortical nuclear masses derived from the telencephalon and located in the basal regions of the cerebral hemispheres.Nerve Net: A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.Compulsive Behavior: The behavior of performing an act persistently and repetitively without it leading to reward or pleasure. The act is usually a small, circumscribed behavior, almost ritualistic, yet not pathologically disturbing. Examples of compulsive behavior include twirling of hair, checking something constantly, not wanting pennies in change, straightening tilted pictures, etc.Startle Reaction: A complex involuntary response to an unexpected strong stimulus usually auditory in nature.Decision Making: The process of making a selective intellectual judgment when presented with several complex alternatives consisting of several variables, and usually defining a course of action or an idea.Amyloid Neuropathies: Disorders of the peripheral nervous system associated with the deposition of AMYLOID in nerve tissue. Familial, primary (nonfamilial), and secondary forms have been described. Some familial subtypes demonstrate an autosomal dominant pattern of inheritance. Clinical manifestations include sensory loss, mild weakness, autonomic dysfunction, and CARPAL TUNNEL SYNDROME. (Adams et al., Principles of Neurology, 6th ed, p1349)Genes, Dominant: Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.Poisons: Substances which, when ingested, inhaled, or absorbed, or when applied to, injected into, or developed within the body in relatively small amounts may, by their chemical action, cause damage to structure or disturbance of function. (From Dorland, 27th ed)Frontal Lobe: The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.Affect: The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves.Caudate Nucleus: Elongated gray mass of the neostriatum located adjacent to the lateral ventricle of the brain.Neural Pathways: Neural tracts connecting one part of the nervous system with another.Anhedonia: Inability to experience pleasure due to impairment or dysfunction of normal psychological and neurobiological mechanisms. It is a symptom of many PSYCHOTIC DISORDERS (e.g., DEPRESSIVE DISORDER, MAJOR; and SCHIZOPHRENIA).Helplessness, Learned: Learned expectation that one's responses are independent of reward and, hence, do not predict or control the occurrence of rewards. Learned helplessness derives from a history, experimentally induced or naturally occurring, of having received punishment/aversive stimulation regardless of responses made. Such circumstances result in an impaired ability to learn. Used for human or animal populations. (APA, Thesaurus of Psychological Index Terms, 1994)Lifting: Moving or bringing something from a lower level to a higher one. The concept encompasses biomechanic stresses resulting from work done in transferring objects from one plane to another as well as the effects of varying techniques of patient handling and transfer.Circadian Clocks: Biological mechanism that controls CIRCADIAN RHYTHM. Circadian clocks exist in the simplest form in cyanobacteria and as more complex systems in fungi, plants, and animals. In humans the system includes photoresponsive RETINAL GANGLION CELLS and the SUPRACHIASMATIC NUCLEUS that acts as the central oscillator.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.Photoperiod: The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.Alpha Rhythm: Brain waves characterized by a relatively high voltage or amplitude and a frequency of 8-13 Hz. They constitute the majority of waves recorded by EEG registering the activity of the parietal and occipital lobes when the individual is awake, but relaxed with the eyes closed.Nucleus Accumbens: Collection of pleomorphic cells in the caudal part of the anterior horn of the LATERAL VENTRICLE, in the region of the OLFACTORY TUBERCLE, lying between the head of the CAUDATE NUCLEUS and the ANTERIOR PERFORATED SUBSTANCE. It is part of the so-called VENTRAL STRIATUM, a composite structure considered part of the BASAL GANGLIA.Choice Behavior: The act of making a selection among two or more alternatives, usually after a period of deliberation.Task Performance and Analysis: The detailed examination of observable activity or behavior associated with the execution or completion of a required function or unit of work.Feedback, Psychological: A mechanism of information stimulus and response that may control subsequent behavior, cognition, perception, or performance. (From APA Thesaurus of Psychological Index Terms, 8th ed.)Amygdala: Almond-shaped group of basal nuclei anterior to the INFERIOR HORN OF THE LATERAL VENTRICLE of the TEMPORAL LOBE. The amygdala is part of the limbic system.Cognition: Intellectual or mental process whereby an organism obtains knowledge.Fear: The affective response to an actual current external danger which subsides with the elimination of the threatening condition.Anxiety: Feeling or emotion of dread, apprehension, and impending disaster but not disabling as with ANXIETY DISORDERS.Pain: An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.Mental Processes: Conceptual functions or thinking in all its forms.Individuality: Those psychological characteristics which differentiate individuals from one another.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Volition: Voluntary activity without external compulsion.Behavior, Animal: The observable response an animal makes to any situation.Conflict (Psychology): The internal individual struggle resulting from incompatible or opposing needs, drives, or external and internal demands. In group interactions, competitive or opposing action of incompatibles: antagonistic state or action (as of divergent ideas, interests, or persons). (from Merriam-Webster's Collegiate Dictionary, 10th ed)Biological Clocks: The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.Corpus Striatum: Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Fathers: Male parents, human or animal.Deoxyguanine Nucleotides: Guanine nucleotides which contain deoxyribose as the sugar moiety.Phycomyces: A genus of zygomycetous fungi in the family Mucoraceae, order MUCORALES, forming mycelia having a metallic sheen. It has been used for research on phototropism.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Placebo Effect: An effect usually, but not necessarily, beneficial that is attributable to an expectation that the regimen will have an effect, i.e., the effect is due to the power of suggestion.Avoidance Learning: A response to a cue that is instrumental in avoiding a noxious experience.Functional Laterality: Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.Hand Strength: Force exerted when gripping or grasping.Limbic System: A set of forebrain structures common to all mammals that is defined functionally and anatomically. It is implicated in the higher integration of visceral, olfactory, and somatic information as well as homeostatic responses including fundamental survival behaviors (feeding, mating, emotion). For most authors, it includes the AMYGDALA; EPITHALAMUS; GYRUS CINGULI; hippocampal formation (see HIPPOCAMPUS); HYPOTHALAMUS; PARAHIPPOCAMPAL GYRUS; SEPTAL NUCLEI; anterior nuclear group of thalamus, and portions of the basal ganglia. (Parent, Carpenter's Human Neuroanatomy, 9th ed, p744; NeuroNames, http://rprcsgi.rprc.washington.edu/neuronames/index.html (September 2, 1998)).Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Probability Learning: Usually refers to the use of mathematical models in the prediction of learning to perform tasks based on the theory of probability applied to responses; it may also refer to the frequency of occurrence of the responses observed in the particular study.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.Evoked Potentials: Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.Motor Activity: The physical activity of a human or an animal as a behavioral phenomenon.Family Health: The health status of the family as a unit including the impact of the health of one member of the family on the family as a unit and on individual family members; also, the impact of family organization or disorganization on the health status of its members.Association Learning: The principle that items experienced together enter into a connection, so that one tends to reinstate the other.Spinocerebellar Ataxias: A group of dominantly inherited, predominately late-onset, cerebellar ataxias which have been divided into multiple subtypes based on clinical features and genetic mapping. Progressive ataxia is a central feature of these conditions, and in certain subtypes POLYNEUROPATHY; DYSARTHRIA; visual loss; and other disorders may develop. (From Joynt, Clinical Neurology, 1997, Ch65, pp 12-17; J Neuropathol Exp Neurol 1998 Jun;57(6):531-43)Putamen: The largest and most lateral of the BASAL GANGLIA lying between the lateral medullary lamina of the GLOBUS PALLIDUS and the EXTERNAL CAPSULE. It is part of the neostriatum and forms part of the LENTIFORM NUCLEUS along with the GLOBUS PALLIDUS.Time Perception: The ability to estimate periods of time lapsed or duration of time.Neuropsychological Tests: Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.Impulsive Behavior: An act performed without delay, reflection, voluntary direction or obvious control in response to a stimulus.Depressive Disorder, Major: Marked depression appearing in the involution period and characterized by hallucinations, delusions, paranoia, and agitation.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Judgment: The process of discovering or asserting an objective or intrinsic relation between two objects or concepts; a faculty or power that enables a person to make judgments; the process of bringing to light and asserting the implicit meaning of a concept; a critical evaluation of a person or situation.Pain Measurement: Scales, questionnaires, tests, and other methods used to assess pain severity and duration in patients or experimental animals to aid in diagnosis, therapy, and physiological studies.Periaqueductal Gray: Central gray matter surrounding the CEREBRAL AQUEDUCT in the MESENCEPHALON. Physiologically it is probably involved in RAGE reactions, the LORDOSIS REFLEX; FEEDING responses, bladder tonus, and pain.Rats, Long-Evans: An outbred strain of rats developed in 1915 by crossing several Wistar Institute white females with a wild gray male. Inbred strains have been derived from this original outbred strain, including Long-Evans cinnamon rats (RATS, INBRED LEC) and Otsuka-Long-Evans-Tokushima Fatty rats (RATS, INBRED OLETF), which are models for Wilson's disease and non-insulin dependent diabetes mellitus, respectively.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Parietal Lobe: Upper central part of the cerebral hemisphere. It is located posterior to central sulcus, anterior to the OCCIPITAL LOBE, and superior to the TEMPORAL LOBES.Conditioning, Classical: Learning that takes place when a conditioned stimulus is paired with an unconditioned stimulus.Thalamus: Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.Diagnostic and Statistical Manual of Mental Disorders: Categorical classification of MENTAL DISORDERS based on criteria sets with defining features. It is produced by the American Psychiatric Association. (DSM-IV, page xxii)Speech: Communication through a system of conventional vocal symbols.Colorectal Neoplasms, Hereditary Nonpolyposis: A group of autosomal-dominant inherited diseases in which COLON CANCER arises in discrete adenomas. Unlike FAMILIAL POLYPOSIS COLI with hundreds of polyps, hereditary nonpolyposis colorectal neoplasms occur much later, in the fourth and fifth decades. HNPCC has been associated with germline mutations in mismatch repair (MMR) genes. It has been subdivided into Lynch syndrome I or site-specific colonic cancer, and LYNCH SYNDROME II which includes extracolonic cancer.Pursuit, Smooth: Eye movements that are slow, continuous, and conjugate and occur when a fixed object is moved slowly.DNA Mismatch Repair: A DNA repair pathway involved in correction of errors introduced during DNA replication when an incorrect base, which cannot form hydrogen bonds with the corresponding base in the parent strand, is incorporated into the daughter strand. Excinucleases recognize the BASE PAIR MISMATCH and cause a segment of polynucleotide chain to be excised from the daughter strand, thereby removing the mismatched base. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Sex Characteristics: Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.Stress, Psychological: Stress wherein emotional factors predominate.Eating: The consumption of edible substances.Schizophrenia: A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.Food Deprivation: The withholding of food in a structured experimental situation.Eye Movements: Voluntary or reflex-controlled movements of the eye.Hand: The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Taste: The ability to detect chemicals through gustatory receptors in the mouth, including those on the TONGUE; the PALATE; the PHARYNX; and the EPIGLOTTIS.Auditory Perception: The process whereby auditory stimuli are selected, organized, and interpreted by the organism.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.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.Dopamine: One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Schizophrenic Psychology: Study of mental processes and behavior of schizophrenics.Pain Threshold: Amount of stimulation required before the sensation of pain is experienced.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.Reinforcement (Psychology): The strengthening of a conditioned response.Conditioning (Psychology): A general term referring to the learning of some particular response.Salsola: A plant genus of the family CHENOPODIACEAE. The extract may be called lochein. Tumbleweed may occasionally refer to AMARANTHUS.Herbaspirillum: A genus of gram-negative bacteria in the family OXALOBACTERACEAE, comprised of vibrioid or sometimes helical cells. They are chemoorganotrophic nitrogen fixers and are found free-living in the soil or in association with the roots of members of the GRAMINEAE. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Regression Analysis: Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.Linear Models: Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.Motion Perception: The real or apparent movement of objects through the visual field.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Rotation: Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Saccades: An abrupt voluntary shift in ocular fixation from one point to another, as occurs in reading.Mothers: Female parents, human or animal.Bias (Epidemiology): Any deviation of results or inferences from the truth, or processes leading to such deviation. Bias can result from several sources: one-sided or systematic variations in measurement from the true value (systematic error); flaws in study design; deviation of inferences, interpretations, or analyses based on flawed data or data collection; etc. There is no sense of prejudice or subjectivity implied in the assessment of bias under these conditions.Data Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Forecasting: The prediction or projection of the nature of future problems or existing conditions based upon the extrapolation or interpretation of existing scientific data or by the application of scientific methodology.Saliva: The clear, viscous fluid secreted by the SALIVARY GLANDS and mucous glands of the mouth. It contains MUCINS, water, organic salts, and ptylin.Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.Psychophysics: The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.Color Perception: Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.Pattern Recognition, Visual: Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.Hydrocortisone: The main glucocorticoid secreted by the ADRENAL CORTEX. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions.Genetic Predisposition to Disease: A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.Macaca mulatta: A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.Risk-Taking: Undertaking a task involving a challenge for achievement or a desirable goal in which there is a lack of certainty or a fear of failure. It may also include the exhibiting of certain behaviors whose outcomes may present a risk to the individual or to those associated with him or her.Family: A social group consisting of parents or parent substitutes and children.

Age of onset in Huntington disease: sex specific influence of apolipoprotein E genotype and normal CAG repeat length. (1/46)

Age of onset (AO) of Huntington disease (HD) is known to be correlated with the length of an expanded CAG repeat in the HD gene. Apolipoprotein E (APOE) genotype, in turn, is known to influence AO in Alzheimer disease, rendering the APOE gene a likely candidate to affect AO in other neurological diseases too. We therefore determined APOE genotype and normal CAG repeat length in the HD gene for 138 HD patients who were previously analysed with respect to CAG repeat length. Genotyping for APOE was performed blind to clinical information. In addition to highlighting the effect of the normal repeat length upon AO in maternally inherited HD and in male patients, we show that the APOE epsilon2epsilon3 genotype is associated with significantly earlier AO in males than in females. Such a sex difference in AO was not apparent for any of the other APOE genotypes. Our findings suggest that subtle differences in the course of the neurodegeneration in HD may allow interacting genes to exert gender specific effects upon AO.  (+info)

Genetics of the SCA6 gene in a large family segregating an autosomal dominant "pure" cerebellar ataxia. (2/46)

Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant cerebellar degeneration caused by the expansion of a CAG trinucleotide repeat in the CACNA1A gene. Mutations in patients are characterised by expanded alleles of between 21 and 30 repeat units and by extreme gonadal stability when transmitted from parents to children. We have investigated the SCA6 mutation in a large Spanish kindred in which previously reported spinocerebellar SCA genes and loci had been excluded. We observed a 23 CAG repeat expanded allele in the 13 clinically affected subjects and in three out of 10 presymptomatic at risk subjects. Transmission of the mutant allele was stable in six parent to child pairs and in 29 meioses through the pedigree. Linkage analysis with the SCA6-CAG polymorphism and marker D19S221 confirmed the location of SCA6 on chromosome 19p13. The molecular findings in this large family confirm the expansion of the CAG repeat in the CACNA1A gene as the cause of SCA6 and the high meiotic stability of the repeat.  (+info)

Why children with inflammatory bowel disease are diagnosed at a younger age than their affected parent. (3/46)

BACKGROUND: Genetic anticipation has been proposed to explain observed age differences at diagnosis of Crohn's disease in affected parents and offspring. AIMS: To compare affected parent-child pairs with Crohn's disease and ulcerative colitis with a control group of non-familial patients with inflammatory bowel disease (IBD) in order to quantify whether ascertainment bias could account for this effect. METHODS: 137 affected parent-child pairs from 96 families and 214 patients with sporadic IBD were studied. Age at onset of symptoms and diagnosis were ascertained by interview and disease confirmed from clinical records. RESULTS: Of the 137 affected parent-child pairs, 50 had Crohn's disease only, 51 had ulcerative colitis only, and in 36, one had Crohn's disease and the other ulcerative colitis. The median age of parents at diagnosis was 17.5 years older, 16 years older, and 18 years older in the Crohn's disease, ulcerative colitis, and mixed disease families respectively (p<0.001 in each case). These observed age differences were compatible with those predicted from the regression lines of years of birth against age at diagnosis for the non-familial IBD patients. No evidence was found for an effect of parental sex on age at diagnosis or disease extent in offspring. CONCLUSIONS: There was no evidence of genetic anticipation or genomic imprinting of age at diagnosis in this sample of IBD families. Ascertainment bias is responsible for the age differences at diagnosis between affected parents and children.  (+info)

Identification of a locus on chromosome 14q for idiopathic basal ganglia calcification (Fahr disease). (4/46)

Idiopathic basal ganglia calcification (IBGC) is a neurodegenerative syndrome that is associated with a variety of movement disorders and neurobehavioral and cognitive manifestations. Despite numerous clinical, pathological, and biochemical investigations, its etiology remains unknown. We have identified a multigenerational family with dominantly inherited IBGC and, in 24 members of this family, performed a whole-genome scan using polymorphic microsatellite markers to identify the first chromosomal locus for this disorder (IBGC1). A maximum two-point LOD score of 3.37 was obtained at marker D14S1014, and a maximum multipoint LOD score of 4.95 was obtained between D14S75 and D14S306. The minimal haplotype shared by affected patients extended over a 17.1-cM region bounded by D14S70 and D14S66, which is potentially further narrowed to a 13.3-cM region by a recombination observed in a patient with probable affected status. The age at onset appeared to be decreasing by an average of >20 years with each transmission, which is consistent with genetic anticipation.  (+info)

Very large (CAG)(n) DNA repeat expansions in the sperm of two spinocerebellar ataxia type 7 males. (5/46)

Genetic anticipation, i.e. increasing disease severity and decreasing age of onset from one generation to the next, is observed in a number of diseases, including myotonic dystrophy type 1, Huntington's disease and several of the spinocerebellar ataxias. All of these disorders are associated with the expansion of a trinucleotide repeat and array length is positively correlated with disease severity and inversely correlated with the age of onset. The expanded repeat is highly unstable and continues to expand from one generation to the next, providing a molecular explanation for anticipation. Spinocerebellar ataxia type 7 (SCA7) is one of the latest additions to the list of triplet repeat diseases and is distinct from the other SCAs in that it is accompanied by retinal degeneration. Pedigree analyses have previously revealed that the SCA7 repeat is highly unstable and liable to expand, in particular when transmitted by a male. Surprisingly, though, an under-representation of male transmission has also been reported. We now demonstrate directly by single molecule analyses that the expanded repeat is extraordinarily unstable in the male germline and biased toward massive increases. Nearly all of the mutant sperm of two SCA7 males contain alleles that are so large that most of the affected offspring would at best have a severe infantile form of the disease. Indeed, the gross under-representation of such very large expanded alleles in patients suggests that a significant proportion of such alleles might be associated with embryonic lethality or dysfunctional sperm.  (+info)

Clinical and molecular advances in autosomal dominant cerebellar ataxias: from genotype to phenotype and physiopathology. (6/46)

Major advances have been made in the understanding of autosomal dominant cerebellar ataxias since genetic markers came into use in the 1980s. The subsequent mapping of nine genes, six of which have been identified, involved in this clinically diverse group of disorders highlighted their great genetic heterogeneity. Evidence is now accumulating that, except for SCA8, the same molecular and physiopathological processes underlie these diseases and other neurodegenerative disorders sharing the same mutational basis, the expansion of a (CAG)n-polyglutamine coding sequence. The clinical overlap among the different genetic entities makes prediction of the molecular origin impossible in a single patient so that molecular characterisation is necessary. However, extended clinical and neuropathological comparisons have shown that each genetic entity has a characteristic constellation of signs and symptoms that are related to CAG repeat size and disease duration. The combined genetic and clinical information form the basis of a new classification that will aid better understanding of disease evolution, assure follow up and permit genetic counselling by the clinician.  (+info)

Structural basis for triplet repeat disorders: a computational analysis. (7/46)

MOTIVATION: Over a dozen major degenerative disorders, including myotonic distrophy, Huntington's disease and fragile X syndrome, result from unstable expansions of particular trinucleotides. Remarkably, only some of all the possible triplets, namely CAG/CTG, CGG/CCG and GAA/TTC, have been associated with the known pathological expansions. This raises some basic questions at the DNA level. Why do particular triplets seem to be singled out? What is the mechanism for their expansion and how does it depend on the triplet itself? Could other triplets or longer repeats be involved in other diseases? RESULTS: Using several different computational models of DNA structure, we show that the triplets involved in the pathological repeats generally fall into extreme classes. Thus, CAG/CTG repeats are particularly flexible, whereas GCC, CGG and GAA repeats appear to display both flexible and rigid (but curved) characteristics depending on the method of analysis. The fact that (1) trinucleotide repeats often become increasingly unstable when they exceed a length of approximately 50 repeats, and (2) repeated 12-mers display a similar increase in instability above 13 repeats, together suggest that approximately 150 bp is a general threshold length for repeat instability. Since this is about the length of DNA wrapped up in a single nucleosome core particle, we speculate that chromatin structure may play an important role in the expansion mechanism. We furthermore suggest that expansion of a dodecamer repeat, which we predict to have very high flexibility, may play a role in the pathogenesis of the neurodegenerative disorder multiple system atrophy (MSA). CONTACT: [email protected], [email protected], [email protected], [email protected]  (+info)

Complex patterns of male germline instability and somatic mosaicism in myotonic dystrophy type 1. (8/46)

The genetic basis of myotonic dystrophy type 1 (DM1) is the expansion of a CTG repeat in the 3' untranslated region of DM1PK. Once into the disease range, the repeat becomes highly unstable and is biased toward expansion in both somatic and germline tissues. Intergenerational differences usually reveal an increase in allele length, concordant with the clinical anticipation characteristic of DM1, but there have also been cases with intergenerational contractions of the repeat length, accompanied by apparent anticipation. In order to gain a better understanding of this intergenerational behaviour, we have obtained semen samples from six DM males and used single molecule analyses to compare the allele distributions present in their sperm and blood with those of their offspring. We have confirmed that the male germline mutational pathway is distinct from that of the soma, but the extent of variation is highly variable from one individual to another and not obviously correlated with progenitor allele length. Nonetheless, in all cases the alleles present in the father's sperm overlap with those observed in their offspring. These data also provide further indications that the interpretation of intergenerational transmissions by standard analyses is frequently compromised by the masking of germline differences by age-dependent somatic expansion in the parent.  (+info)

  • LS-associated gene-specific anticipation effects are evident for MSH2 (2.6 years/generation for NREM and hazard ratio of 1.33 for COX-R) and PMS2 (7.3 years/generation and hazard ratio of 1.86). (cdc.gov)
  • We then consider the evidence from genetic studies, including investigations of gene by environment (GxE) interactions and epigenetic effects in humans and animals, relating these to possible mechanisms associated with vulnerability and resilience. (frontiersin.org)
  • With public safety, gene patents, and the future of genetic research at stake, a wide range of interest groups competed for control over this powerful new technology. (uchicago.edu)
  • Given this non-specific presentation and the widely available technical means of studying the TTR gene, we believe that the protocol for the aetiological diagnosis of any polyneuropathy should include genetic sequencing of TTR. (elsevier.es)
  • Each genetic trait has two genes, which might be identical or might include one gene that is dominant and one that is recessive. (howstuffworks.com)
  • By combining studies of tissue-specific gene expression, male courtship song, low-dose fungal infections and immune gene knockdowns assays, the authors hope to identify the genetic links between brain, behaviour and immunity. (phys.org)
  • Most genetic disorders have signs and symptoms that differ among affected individuals, including affected people in the same family. (medlineplus.gov)
  • Spinocerebellar ataxia (SCA) is one of a group of genetic disorders characterized by slowly progressive incoordination of gait and is often associated with poor coordination of hands, speech, and eye movements. (wikipedia.org)
  • citation needed] There are numerous types of autosomal-dominant cerebellar ataxias There are five typical autosomal recessive disorders in which ataxia is a prominent feature A few SCAs remain unspecified and can not be precisely diagnosed, but in the last decade genetic testing has allowed precise identification of dozens of different SCAs and more tests are being added each year. (wikipedia.org)
  • This genetic mechanism may explain how dopamine levels increase when people anticipate a reward and why problems with reward processing are found in people with various mental disorders, including attention deficit hyperactivity disorder (ADHD) and addictions such as alcohol abuse. (kcl.ac.uk)
  • Professor Gunter Schumann , senior author of the paper from the MRC Social, Genetic and Developmental Psychiatry (SGDP) Centre at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London, and Coordinator of the IMAGEN project, said: 'We already know that reward-related disorders, such as ADHD and alcohol abuse, often occur simultaneously. (kcl.ac.uk)
  • Psychiatric disorders are thought to have a complex genetic pathology consisting of interplay of common and rare variation. (nature.com)
  • We illustrate our discussion by investigating the relationship between PRS and apparent assortative mating, and anticipation within a complex multigenerational pedigree affected with mood disorders. (nature.com)
  • The better known genetic disorders include sickle cell anemia, Tay-Sachs disease, and cystic fibrosis, which are more prevalent among certain demographic groups. (howstuffworks.com)
  • First are classic descriptions of important genetic disorders, often from the pre-mendelian era. (oup.com)
  • An unconventional approach has successfully reversed deficits in social behaviors associated with autism spectrum disorders (ASD) in genetic, environmental and idiopathic mouse models of the condition. (neurosciencenews.com)
  • If you are 35 or older, if you have had an abnormal ultrasound or blood screening, or if you have a family history of birth defects or genetic disorders, you may be high-risk. (clevelandclinic.org)
  • Known susceptibility genes account for less than 25% of the familial risk of breast cancer, and the residual genetic variance is likely to be due to variants conferring more moderate risks. (gnxp.com)
  • Thus, for every genetic trait, there are two genes. (howstuffworks.com)
  • By analysing the genetic make-up and immunity of over 100,000 fruit flies the scientists were able to understand how genes are switched on and off in order to prevent infections. (phys.org)
  • Harboring mobile genetic elements generally creates a cost to the host, associated with the replication and maintenance of the genetic element and with the expression of its genes. (prolekare.cz)
  • The common polymorphic codon 129 of PRNP also plays an important and complex role in risk and phenotype of sporadic and genetic prion disease. (nature.com)
  • The genetic constitution of an organism, which is modulated by the environment before being expressed as a phenotype. (bmj.com)
  • Since substantial variation in the phenotype is observed for different populations, epigenetic/genetic and/or environmental factors must exert a significant impact on the penetrance of the disease. (diva-portal.org)
  • A tendency of a disease to cluster in families, which is generally taken as evidence for the existence of a genetic aetiological mechanism, or environmental factors common to family members, or a combination of both. (bmj.com)
  • The signs and symptoms of some genetic conditions tend to become more severe and appear at an earlier age as the disorder is passed from one generation to the next. (medlineplus.gov)
  • Conclusions: Patients in the second affected generation seem to acquire the disease at an earlier time in life, indicating strong evidence of anticipation. (elsevier.com)
  • Some families show a pattern of disease called anticipation, with symptoms developing earlier in each new generation. (encyclopedia.com)
  • As we said in an earlier discussion, genetic diversity is important because it allows plants to adapt to changing environments. (garden.org)
  • Interestingly, the different populations all display a maternal anticipation, where an earlier onset is observed for those individuals who inherit the trait from their mother. (diva-portal.org)
  • We conclude by exploring the extent to which the growing evidence base in relation to neurobiological and genetic research may be relevant to clinical practice and intervention. (frontiersin.org)
  • Herein, we briefly summarize clinical and genetic aspects of this aggressive cancer predisposition syndrome. (aacrjournals.org)
  • With sub-specialties in glaucoma, cataract, paediatric and genetic ophthalmology and clinical electrophysiology, Prof. Grigg completed his training at Sydney Eye Hospital and undertook fellowships in Australia and the UK.His research interests are genetic eye disease, glaucoma management and electrophysiology of the visual system. (edu.au)
  • Rocio Moran, MD , a clinical geneticist in Cleveland Clinic's Center for Personalized Genetic Healthcare , understands those fears. (clevelandclinic.org)
  • In 2017, Dr. Gregg was invited before Congress to give expert briefing on advances in prenatal genetic screening on behalf of ACMG. (sc.edu)
  • What do geneticists mean by anticipation? (medlineplus.gov)
  • When the genetic portion came back with her testing positive for a scary sounding condition, the Embark geneticists sent a personalized email before releasing the results, letting me know things weren't as bad as it sounded, and explaining further about the condition (including the breed of dog that it typically cause the most issues with) Had I just opened my results and seen this condition I would have PANICKED! (amzn.com)
  • Another reason for variability in drug responses is genetic variation leading to a spectrum of different responses to analgesics, from lack of efficacy to exaggerated responses, up to intolerable adverse effects. (clinicaltrials.gov)
  • While pedigree studies have been traditionally used to explore rare genetic variation through linkage analyses, studying patterns of PRS throughout a pedigree would allow for assessment of phenomena like assortative mating and anticipation. (nature.com)
  • By combining methods from political science and the history of science, Wright advances a provocative interpretation of the evolution of genetic engineering policy and makes a major contribution to science and public policy studies. (uchicago.edu)
  • Likewise, cohort effect, which may be caused by environmental factors, can be misinterpreted as genetic anticipation. (cdc.gov)
  • The analyses were further controlled for ascertainment bias by excluding probands and adjusting for birth-cohort effect in the anticipation models. (cdc.gov)
  • Case in point… just very recently , when dealing with this exact same Miller line, I discovered that I did match one of my cousins at Family Tree DNA on the Miller line, but that we also have a second unknown genetic link on the X chromosome that could not have come from that Miller couple. (dna-explained.com)
  • This is the second of a series of three glossaries on genetic concepts used in epidemiological research that the journal is publishing with the objective of helping the reader "walk" around the journal. (bmj.com)
  • Metal(loid)s role in the pathogenesis of amyotrophic lateral sclerosis: Environmental, epidemiological, and genetic data. (medworm.com)
  • Before genetic screening, babies with the disorder usually died, often misdiagnosed as Reye's syndrome or SIDS. (theatlantic.com)
  • Morriss found herself pondering the genetic nature of the disorder. (theatlantic.com)
  • I was looking at several tests (both more and less expensive than this one) and decided on Embark because of the genetic disorder portion of the text. (amzn.com)
  • The effect sizes at many individual single-nucleotide polymorphisms (SNPs), estimated by large genome-wide association studies (GWAS) on the disorder of interest, are used to calculate an individual level genome-wide PRS in individuals from an independent genetic dataset. (nature.com)
  • Some of those variations or genetic changes may only increase your risk of having a particular disorder," Dr. Moran says. (clevelandclinic.org)