Fear: The affective response to an actual current external danger which subsides with the elimination of the threatening condition.Conditioning, Classical: Learning that takes place when a conditioned stimulus is paired with an unconditioned stimulus.Conditioning (Psychology): A general term referring to the learning of some particular response.Freezing Reaction, Cataleptic: An induced response to threatening stimuli characterized by the cessation of body movements, except for those that are involved with BREATHING, and the maintenance of an immobile POSTURE.Extinction, Psychological: The procedure of presenting the conditioned stimulus without REINFORCEMENT to an organism previously conditioned. It refers also to the diminution of a conditioned response resulting from this procedure.Emotions: Those affective states which can be experienced and have arousing and motivational properties.Facial Expression: Observable changes of expression in the face in response to emotional stimuli.Electroshock: Induction of a stress reaction in experimental subjects by means of an electrical shock; applies to either convulsive or non-convulsive states.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.Avoidance Learning: A response to a cue that is instrumental in avoiding a noxious experience.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.Behavior, Animal: The observable response an animal makes to any situation.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.Startle Reaction: A complex involuntary response to an unexpected strong stimulus usually auditory in nature.Neural Pathways: Neural tracts connecting one part of the nervous system with another.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.Anxiety: Feeling or emotion of dread, apprehension, and impending disaster but not disabling as with ANXIETY DISORDERS.Association Learning: The principle that items experienced together enter into a connection, so that one tends to reinstate the other.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.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)).Prefrontal Cortex: The rostral part of the frontal lobe, bounded by the inferior precentral fissure in humans, which receives projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical afferents of visual, auditory, and somatic origin.Galvanic Skin Response: A change in electrical resistance of the skin, occurring in emotion and in certain other conditions.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.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.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.Cues: Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.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.Septal Nuclei: Neural nuclei situated in the septal region. They have afferent and cholinergic efferent connections with a variety of FOREBRAIN and BRAIN STEM areas including the HIPPOCAMPAL FORMATION, the LATERAL HYPOTHALAMUS, the tegmentum, and the AMYGDALA. Included are the dorsal, lateral, medial, and triangular septal nuclei, septofimbrial nucleus, nucleus of diagonal band, nucleus of anterior commissure, and the nucleus of stria terminalis.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.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.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.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.Muscimol: A neurotoxic isoxazole isolated from species of AMANITA. It is obtained by decarboxylation of IBOTENIC ACID. Muscimol is a potent agonist of GABA-A RECEPTORS and is used mainly as an experimental tool in animal and tissue studies.Ibotenic Acid: A neurotoxic isoxazole (similar to KAINIC ACID and MUSCIMOL) found in AMANITA mushrooms. It causes motor depression, ataxia, and changes in mood, perceptions and feelings, and is a potent excitatory amino acid agonist.Proto-Oncogene Proteins c-fos: Cellular DNA-binding proteins encoded by the c-fos genes (GENES, FOS). They are involved in growth-related transcriptional control. c-fos combines with c-jun (PROTO-ONCOGENE PROTEINS C-JUN) to form a c-fos/c-jun heterodimer (TRANSCRIPTION FACTOR AP-1) that binds to the TRE (TPA-responsive element) in promoters of certain genes.Microinjections: The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.Arousal: Cortical vigilance or readiness of tone, presumed to be in response to sensory stimulation via the reticular activating system.Kindling, Neurologic: The repeated weak excitation of brain structures, that progressively increases sensitivity to the same stimulation. Over time, this can lower the threshold required to trigger seizures.Corticotropin-Releasing Hormone: A peptide of about 41 amino acids that stimulates the release of ADRENOCORTICOTROPIC HORMONE. CRH is synthesized by neurons in the PARAVENTRICULAR NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, CRH stimulates the release of ACTH from the PITUITARY GLAND. CRH can also be synthesized in other tissues, such as PLACENTA; ADRENAL MEDULLA; and TESTIS.Exploratory Behavior: The tendency to explore or investigate a novel environment. It is considered a motivation not clearly distinguishable from curiosity.Neuronal Plasticity: The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.Phobic Disorders: Anxiety disorders in which the essential feature is persistent and irrational fear of a specific object, activity, or situation that the individual feels compelled to avoid. The individual recognizes the fear as excessive or unreasonable.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.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)Long-Term Potentiation: A persistent increase in synaptic efficacy, usually induced by appropriate activation of the same synapses. The phenomenological properties of long-term potentiation suggest that it may be a cellular mechanism of learning and memory.Lipoid Proteinosis of Urbach and Wiethe: An autosomal recessive disorder characterized by glassy degenerative thickening (hyalinosis) of SKIN; MUCOSA; and certain VISCERA. This disorder is caused by mutation in the extracellular matrix protein 1 gene (ECM1). Clinical features include hoarseness and skin eruption due to widespread deposition of HYALIN.Reward: An object or a situation that can serve to reinforce a response, to satisfy a motive, or to afford pleasure.Stress, Psychological: Stress wherein emotional factors predominate.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.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.Functional Neuroimaging: Methods for visualizing REGIONAL BLOOD FLOW, metabolic, electrical, or other physiological activities in the CENTRAL NERVOUS SYSTEM using various imaging modalities.Reaction Time: The time from the onset of a stimulus until a response is observed.Pattern Recognition, Visual: Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.Face: The anterior portion of the head that includes the skin, muscles, and structures of the forehead, eyes, nose, mouth, cheeks, and jaw.Retention (Psychology): The persistence to perform a learned behavior (facts or experiences) after an interval has elapsed in which there has been no performance or practice of the behavior.Conditioning, Operant: Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.Social Perception: The perceiving of attributes, characteristics, and behaviors of one's associates or social groups.Social Behavior: Any behavior caused by or affecting another individual, usually of the same species.Anti-Anxiety Agents: Agents that alleviate ANXIETY, tension, and ANXIETY DISORDERS, promote sedation, and have a calming effect without affecting clarity of consciousness or neurologic conditions. ADRENERGIC BETA-ANTAGONISTS are commonly used in the symptomatic treatment of anxiety but are not included here.Receptors, Corticotropin-Releasing Hormone: Cell surface proteins that bind corticotropin-releasing hormone with high affinity and trigger intracellular changes which influence the behavior of cells. The corticotropin releasing-hormone receptors on anterior pituitary cells mediate the stimulation of corticotropin release by hypothalamic corticotropin releasing factor. The physiological consequence of activating corticotropin-releasing hormone receptors on central neurons is not well understood.Synaptic Transmission: The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.Expressed Emotion: Frequency and quality of negative emotions, e.g., anger or hostility, expressed by family members or significant others, that often lead to a high relapse rate, especially in schizophrenic patients. (APA, Thesaurus of Psychological Index Terms, 7th ed)Happiness: Highly pleasant emotion characterized by outward manifestations of gratification; joy.Receptors, N-Methyl-D-Aspartate: A class of ionotropic glutamate receptors characterized by affinity for N-methyl-D-aspartate. NMDA receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity.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.Recognition (Psychology): The knowledge or perception that someone or something present has been previously encountered.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.Cycloserine: Antibiotic substance produced by Streptomyces garyphalus.Thalamus: Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.Anxiety Disorders: Persistent and disabling ANXIETY.Habituation, Psychophysiologic: The disappearance of responsiveness to a repeated stimulation. It does not include drug habituation.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.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.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)Inhibition (Psychology): The interference with or prevention of a behavioral or verbal response even though the stimulus for that response is present; in psychoanalysis the unconscious restraining of an instinctual process.Electric Stimulation: Use of electric potential or currents to elicit biological responses.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.Neuronal Tract-Tracers: Substances used to identify the location and to characterize the types of NEURAL PATHWAYS.Mental Recall: The process whereby a representation of past experience is elicited.Excitatory Amino Acid Antagonists: Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists.Dominance, Cerebral: Dominance of one cerebral hemisphere over the other in cerebral functions.Anger: A strong emotional feeling of displeasure aroused by being interfered with, injured or threatened.Subliminal Stimulation: Stimulation at an intensity below that where a differentiated response can be elicited.Time Factors: Elements of limited time intervals, contributing to particular results or situations.gamma-Aminobutyric Acid: The most common inhibitory neurotransmitter in the central nervous system.GABA Agonists: Endogenous compounds and drugs that bind to and activate GAMMA-AMINOBUTYRIC ACID receptors (RECEPTORS, GABA).Mice, Inbred C57BLOncogene Proteins v-fos: Transforming proteins coded by fos oncogenes. These proteins have been found in the Finkel-Biskis-Jinkins (FBJ-MSV) and Finkel-Biskis-Reilly (FBR-MSV) murine sarcoma viruses which induce osteogenic sarcomas in mice. The FBJ-MSV v-fos gene encodes a p55-kDa protein and the FBR-MSV v-fos gene encodes a p75-kDa fusion protein.Memory, Long-Term: Remembrance of information from 3 or more years previously.Olfactory Pathways: Set of nerve fibers conducting impulses from olfactory receptors to the cerebral cortex. It includes the OLFACTORY NERVE; OLFACTORY BULB; OLFACTORY TRACT; OLFACTORY TUBERCLE; ANTERIOR PERFORATED SUBSTANCE; and OLFACTORY CORTEX.Substance Withdrawal Syndrome: Physiological and psychological symptoms associated with withdrawal from the use of a drug after prolonged administration or habituation. The concept includes withdrawal from smoking or drinking, as well as withdrawal from an administered drug.Escape Reaction: Innate response elicited by sensory stimuli associated with a threatening situation, or actual confrontation with an enemy.Reinforcement (Psychology): The strengthening of a conditioned response.Temporal Lobe: Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the OCCIPITAL LOBE.Taste: The ability to detect chemicals through gustatory receptors in the mouth, including those on the TONGUE; the PALATE; the PHARYNX; and the EPIGLOTTIS.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.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.Serotonin Plasma Membrane Transport Proteins: Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of serotonergic neurons. They are different than SEROTONIN RECEPTORS, which signal cellular responses to SEROTONIN. They remove SEROTONIN from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. Regulates signal amplitude and duration at serotonergic synapses and is the site of action of the SEROTONIN UPTAKE INHIBITORS.Stress Disorders, Post-Traumatic: A class of traumatic stress disorders with symptoms that last more than one month. There are various forms of post-traumatic stress disorder, depending on the time of onset and the duration of these stress symptoms. In the acute form, the duration of the symptoms is between 1 to 3 months. In the chronic form, symptoms last more than 3 months. With delayed onset, symptoms develop more than 6 months after the traumatic event.Synapses: Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Dental Anxiety: Abnormal fear or dread of visiting the dentist for preventive care or therapy and unwarranted anxiety over dental procedures.Neural Inhibition: The function of opposing or restraining the excitation of neurons or their target excitable cells.GABA-A Receptor Agonists: Endogenous compounds and drugs that bind to and activate GABA-A RECEPTORS.Individuality: Those psychological characteristics which differentiate individuals from one another.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.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.Electrodes, Implanted: Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.Excitatory Postsynaptic Potentials: Depolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during neurotransmission. Excitatory postsynaptic potentials can singly or in summation reach the trigger threshold for ACTION POTENTIALS.Motor Activity: The physical activity of a human or an animal as a behavioral phenomenon.Hypothalamus: Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.Anisomycin: An antibiotic isolated from various Streptomyces species. It interferes with protein and DNA synthesis by inhibiting peptidyl transferase or the 80S ribosome system.Panic: A state of extreme acute, intense anxiety and unreasoning fear accompanied by disorganization of personality function.Prosencephalon: The anterior of the three primitive cerebral vesicles of the embryonic brain arising from the NEURAL TUBE. It subdivides to form DIENCEPHALON and TELENCEPHALON. (Stedmans Medical Dictionary, 27th ed)Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.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.Aggression: Behavior which may be manifested by destructive and attacking action which is verbal or physical, by covert attitudes of hostility or by obstructionism.Pain: An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.Discrimination (Psychology): Differential response to different stimuli.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.Cocaine: An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake.GABA Antagonists: Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.Bipolar Disorder: A major affective disorder marked by severe mood swings (manic or major depressive episodes) and a tendency to remission and recurrence.Neuropeptide Y: A 36-amino acid peptide present in many organs and in many sympathetic noradrenergic neurons. It has vasoconstrictor and natriuretic activity and regulates local blood flow, glandular secretion, and smooth muscle activity. The peptide also stimulates feeding and drinking behavior and influences secretion of pituitary hormones.Behavior: The observable response of a man or animal to a situation.Choice Behavior: The act of making a selection among two or more alternatives, usually after a period of deliberation.Ethanol: A clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in ALCOHOLIC BEVERAGES.Receptors, AMPA: A class of ionotropic glutamate receptors characterized by their affinity for the agonist AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid).Substantia Innominata: Tissue in the BASAL FOREBRAIN inferior to the anterior perforated substance, and anterior to the GLOBUS PALLIDUS and ansa lenticularis. It contains the BASAL NUCLEUS OF MEYNERT.
  • Taken together, these findings reveal a novel, obligatory role for amygdala eCBs in the proextinction effects of a major pharmacotherapy for trauma- and stressor-related disorders and anxiety disorders. (nature.com)
  • Filling these gaps in our knowledge is important because much evidence indicates that human anxiety disorders results from an abnormal regulation of the networks supporting fear learning. (nih.gov)
  • Amygdala dysfunction has also been implicated in human disorders ranging from social anxiety (Birbaumer et al. (psu.edu)
  • show interaction between the gut microbes and expression of anxiety and fear regulated by the amygdala. (dericbownds.net)
  • The amygdala is a key brain region that is critically involved in the processing and expression of anxiety and fear-related signals. (dericbownds.net)
  • These results suggest a gain of function in fear regulation and may indicate for whom and for what anxiety symptoms FAAH inhibitors or exposure-based therapies will be most efficacious, bridging an important translational gap between the mouse and human. (nature.com)
  • Finnish researchers at the University of Eastern Finland and the University of Oulu have discovered of a new type of gene mutation that reduces fear and anxiety, and increases social interaction. (news-medical.net)
  • A new study finds that veterans and active-duty service members with combat-related PTSD and mild traumatic brain injury had larger amygdalas--the region of the brain that processes such emotions as fear, anxiety, and aggression--than those with only brain injuries. (news-medical.net)
  • A dimensional analysis approach was used involving voxel-wise mapping of the correlation between subjects' social anxiety scores and amygdala activation, before and after controlling for fusiform gyrus activation. (cambridge.org)
  • We observed that only after controlling for subjects' level of activation of the fusiform gyrus was there an association between social anxiety ratings and amygdala response to both happy and fearful faces. (cambridge.org)
  • Amygdala activation in the processing of neutral faces in social anxiety disorder: is neutral really neutral? (cambridge.org)
  • Anxiety a core feature of panic disorder, is linked to function of the amygdala. (wiley.com)
  • Volume alterations in the brain of patients with panic disorder have previously been reported, but there has been no report of amygdala volume association with anxiety. (wiley.com)
  • These findings suggested that the smaller volume of the amygdala may be associated with anxiety in panic disorder. (wiley.com)
  • PANIC DISORDER (PD) is a complex anxiety disorder characterized by recurrent episodes of sudden and uncontrollable fear (panic attack) and autonomic imbalance such as palpitation, perspiration, trembling, shortness of breath, a sense of suffocation, chest pain or discomfort, nausea or gastrointestinal discomfort, and dizziness. (wiley.com)
  • Much evidence suggests that human anxiety disorders result from anomalies in amygdala function. (grc.org)
  • Findings from this project will have important clinical implications, as impairments in fear processing and fear regulation are core features of several anxiety disorders, including post-traumatic stress disorder (PTSD). (grantome.com)
  • Furthermore, we found significant relationships between FMR1 gene expression, anxiety/social dysfunction scores, and reduced amygdala activation in the FX group. (elsevier.com)
  • In my final unit of Master's study, I have become increasingly aware of the important role that the amygdala plays in stress-management and anxiety-reduction. (ausmed.com.au)
  • Neuro-imaging has shown increased amygdala activation for various anxiety disorders (Shin & Liberzon, 2010). (ausmed.com.au)
  • Generalized anxiety disorder has been linked to disrupted functional connectivity of the amygdala and its processing of fear and anxiety. (wikipedia.org)
  • The latter suggests a compensation strategy for dysfunctional amygdala processing of anxiety. (wikipedia.org)
  • This section of the brain is also involved in emotions, specifically fear and anxiety. (wikihow.com)
  • However, a number of non-motor symptoms, including pathological fear and anxiety, predate the emergence of motor impairment. (uibk.ac.at)
  • Using this method, exposure therapy 1) gradually exposes you to anxiety producing situations, 2) helps you to stay in place and give your brain time to adjust by using a variety of coping skills, and 3) affects changes in your brain, allowing your amygdala to form new associations. (childteenfamilytherapy.com)
  • Disorders of anxiety, assaults of panic, phobias, fears, The evolution in the STUDIES ABOUT brain has ADVANCED A LOT from 1968, when it was achieved to obtain the first not invasive image of diagnosis of the governing organ of the nervous system. (prezi.com)
  • The Alzheimer's Disease Research website notes that this area of the brain has many functions including developing, associating and remembering reflexive emotions such as fear and anxiety. (livestrong.com)
  • Many studies have shown the key role played by the mammalian amygdaloid circuits in aversive memory, and most of them have considered the participation of the rodent amygdala in fear conditioning (1-3). (scielo.br)
  • A sparse neuronal representation for fear, here revealed by multivariate pattern classification, resolves why an enduring memory trace has proven elusive in previous human studies. (jneurosci.org)
  • We also assessed changes in neuronal transcription and post-transcriptional regulation in the amygdala of naive and stimulated germ-free (GF) mice, using a genome-wide transcriptome profiling approach. (dericbownds.net)
  • Together, our data demonstrates a unique transcriptional response in GF animals, likely because of already elevated levels of immediate-early gene expression and the potentially underlying neuronal hyperactivity that in turn primes the amygdala for a different transcriptional response. (dericbownds.net)
  • Changes in neuronal connectivity occurring upon the formation of aversive memory were examined in C57BL/6 (C57) mice 24 h after they were trained for tone fear conditioning (TFC) and contextual fear conditioning (CFC). (frontiersin.org)
  • In birds, the arcopallium includes several neuronal populations that are considered to be homologous to the regions that constitute the mammalian amygdala. (scielo.br)
  • Utilizing anatomical, electrophysiological, imaging and optogenetics approaches the authors of the study were able to analyze individual neuronal cells connecting the auditory cortex and the lateral amygdala in the brains of mice. (neuro-central.com)
  • In this study, we found predominant neuronal projections of serotonergic, dopaminergic and cholinergic fibers in the basolateral amygdala (BLA), and CB1 receptor was frequently localized on serotonergic axon but not dopaminergic, noradrenergic or cholinergic fibers. (nii.ac.jp)
  • We measured the effects of glutamate (0.1-1000 μ M ) and N -methyl- d -aspartate (NMDA, 0.1-1000 μM) on CRF release from the amygdala using primary neuronal cultures from embryonic rat brains (E18-19). (deepdyve.com)
  • These results indicate that the amygdala is not required for fear and panic, and make an important distinction between fear triggered by external threats from the environment versus fear triggered internally by CO2. (medicalxpress.com)
  • Animal models indicate that the amygdala orchestrates stressor-evoked blood pressure reactions via reciprocal signaling with corticolimbic and brainstem cardiovascular-regulatory circuits. (pubmedcentralcanada.ca)
  • Glutamate and γ-aminobutyric acid (GABA) release in the amygdala are thought to be crucial for the acquisition and expression of fear memories, but the time course of amino acid changes during conditioning is unknown. (umich.edu)
  • Few studies have evaluated neurotransmitter-stimulated CRF release in the amygdala. (deepdyve.com)
  • These results implicate an inhibition of CRF release in the amygdala as a possible mechanism for the reported anxiolytic effects of NMDA antagonists. (deepdyve.com)
  • Detailed studies of autism-related genes, such as neurexin and neuroligin, are likely to be highly informative about the nature of dysfunction associated with autism, particularly in the amygdala, the researchers say. (sfari.org)
  • Here, we investigated amygdala dysfunction and its relation to socioemotional deficits and FMR1 gene expression in children and adolescents on the FX spectrum (i.e., individuals whose trinucleotide CGG repeat expansion from 55 to over 200 places them somewhere within the fragile X diagnostic range from premutation to full mutation). (elsevier.com)
  • GABAergic signaling in the amygdala controls learned fear, and its dysfunction potentially contributes to posttraumatic stress disorder (PTSD). (postech.ac.kr)
  • Not only did stimulating serotonin nerve terminals reduce amygdala activity, but the chemogenetic inhibition of the amygdala using designer receptors exclusively activated by designer drugs also drastically decreased CLEs, whereas chemogenetic activation increased them. (pnas.org)
  • We further propose that these memory traces act to promote the inhibition of CeL output during fear memory recall, thereby disinhibiting CeM and releasing fear expression. (grantome.com)
  • The results of this study demonstrate that, by suppressing excitatory and inhibitory transmission, activation of presynaptic GABA B -receptors in the CeA inhibits the development of context conditioned fear. (edu.au)
  • However, the anterodorsal BNST subdivision (adBNST) was not activated during either contextual fear conditioning or retrieval, underscoring the divergent functionality of these two dBNST subdivisions. (eneuro.org)
  • To examine the impact of GABA B -receptors in the CeA on contextual fear-conditioning, we infused baclofen into the CeA immediately prior to training. (edu.au)
  • Relative to placebo, alcohol reduced functional coupling between the amygdala and the right orbitofrontal cortex (OFC) during processing of both angry and fearful faces. (springer.com)
  • Alcohol also reduced functional coupling between the amygdala and left OFC during processing of happy faces. (springer.com)
  • In rodents, fear memory is stored and reactivated under the influence of the amygdala. (jneurosci.org)
  • There is no evidence for an equivalent mechanism in primates, and an opposite mechanism is proposed whereby primate amygdala contributes only to an initial phase of aversive learning, subsequently ceding fear memory to extra-amygdalar regions. (jneurosci.org)
  • The strength of this discrimination increased over time and was tightly coupled to the behavioral expression of fear, consistent with an expression of a stable fear memory trace. (jneurosci.org)
  • These data highlight that the human basolateral and centro-cortical amygdala support initial learning as well more enduring fear memory storage. (jneurosci.org)
  • They also plan to investigate how neurexin is involved in fear memory, a function that is associated with the amygdala. (sfari.org)
  • Thus, we demonstrate for what is to our knowledge the first time that the presence of the host microbiome is crucial for the appropriate behavioural response during amygdala-dependent memory retention. (dericbownds.net)
  • These observations raise a point relevant to aversive memory studies, i.e., how the peculiarity of memory in certain individuals impacts on the components of the fear circuitry. (frontiersin.org)
  • Fear conditioning (FC), the most common model of aversive memory in rodents, is rapidly induced and persists over a considerable period of time. (frontiersin.org)
  • One problem with many of these studies is that the animals were repeatedly stressed before the fear memory was formed. (elifesciences.org)
  • This made it hard to tease apart whether the strength of the fear memory itself or a problem extinguishing the fear memory were to blame for the animals' difficulties overcoming their fear. (elifesciences.org)
  • The report by Alkire and Nathan 4 in this issue of Anesthesiology provides interesting data supporting the amygdala as a site at which inhaled anesthetics exert an amnestic effect on fear conditioning, one form of memory. (asahq.org)
  • These data suggest that, at least for this type of learning, the basolateral amygdala is not the critical site for memory storage and that sevoflurane (and propfol 5 and diazepam 6 ) acts in that structure to block this learning. (asahq.org)
  • The effect of chronic corticosterone on fear learning and memory depends on dose and the testing protocol. (semanticscholar.org)
  • Polysialylated neural cell adhesion molecule is involved in induction of long-term potentiation and memory acquisition and consolidation in a fear-conditioning paradigm. (semanticscholar.org)
  • Using a mouse model of dysregulated fear, we found altered expression within the amygdala of the Oprl1 gene (opioid receptor-like 1), which encodes the amygdala nociceptin (NOP)/orphanin FQ receptor (NOP-R). Systemic and central amygdala infusion of SR-8993, a new highly selective NOP-R agonist, impaired fear memory consolidation. (elsevier.com)
  • Further, our data suggest that activation of the Oprl1/NOP receptor may interfere with fear memory consolidation, with implications for prevention of PTSD after a traumatic event. (elsevier.com)
  • Our central hypothesis is that fear conditioning induces cell type-specific synaptic modifications in CeL circuits that serve as fear memory traces. (grantome.com)
  • The aim of this paper will be to make a comprehensive overview of internal neural processes of both the amygdala and hippocampus and the interaction between the two structures during fear conditioning, to see how the structures separately work to overlap emotion and memory processes. (diva-portal.org)
  • Here, we report that at lateral amygdala (LA) synapses (a storage site for fear memory), conditioning with different types of auditory CSs (2.8 kHz tone, white noise, FM tone) recruits distinct forms of long-term potentiation (LTP) and inserts calcium permeable AMPA receptor (CP-AMPAR) for variable periods. (ewha.ac.kr)
  • The present study examined whether the BLC also modulates the consolidation of memory for classical fear conditioning in which a specific context is paired with footshock. (elsevier.com)
  • Vazdarjanova, A & McGaugh, JL 1999, ' Basolateral amygdala is involved in modulating consolidation of memory for classical fear conditioning ', Journal of Neuroscience , vol. 19, no. 15, pp. 6615-6622. (elsevier.com)
  • Consistently, conditioned fear to 2.8 kHz tone but not to white noise or FM tones was erased by reconsolidation-update (which depends on the insertion of CP-AMPARs at LA synapses) when it was performed 6 hr after conditioning. (ewha.ac.kr)
  • The researchers found that neurexin and its binding partner neuroligin, which is also implicated in autism, are important for inducing and stabilizing synaptic changes related to learned fear. (sfari.org)
  • Medical Xpress)-Researchers at the University of Iowa have found that three volunteer women with defective amygdalas were able to experience internal fear. (medicalxpress.com)
  • The amygdala has been linked to fear since the publication of a 1930s paper by University of Chicago researchers Heinrich Klüver and Paul C. Bucy, who described profound behavioral changes - including a newfound willingness to approach snakes and other dangerous animals - in rhesus monkeys whose temporal lobes, including the amygdala, had been removed. (massgeneral.org)
  • The researchers wrote that the results "provide a mechanistic explanation, on both a synaptic and circuit level, for how positive and negative associations can be rapidly formed, represented, and expressed within the amygdala. (bipolarnews.org)
  • Fear researchers, by addressing this issue, might well set an example that also paves the way for crisper conceptions in other areas of research. (dericbownds.net)
  • UCLA researchers reveal the amygdala has much greater cell diversity than previously believed. (neurosciencenews.com)
  • Researchers from the University of Toronto conducted experiments to analyze the benefits of facial expressions in response to fear. (medindia.net)
  • As a next step, Kandel's team aims to investigate how virally mediated acute suppression of neurexin in the mouse amygdala affects learning-induced changes in synaptic connections. (sfari.org)
  • During auditory fear conditioning, large, rapid and transient increases in glutamate and GABA were detected, but only during the first noise-shock pairing. (umich.edu)