ABSTRACT
To survive in a complex social group, one needs to know who to approach and, more importantly, who to avoid. In mice, a single defeat causes the losing mouse to stay away from the winner for weeks1. Here through a series of functional manipulation and recording experiments, we identify oxytocin neurons in the retrochiasmatic supraoptic nucleus (SOROXT) and oxytocin-receptor-expressing cells in the anterior subdivision of the ventromedial hypothalamus, ventrolateral part (aVMHvlOXTR) as a key circuit motif for defeat-induced social avoidance. Before defeat, aVMHvlOXTR cells minimally respond to aggressor cues. During defeat, aVMHvlOXTR cells are highly activated and, with the help of an exclusive oxytocin supply from the SOR, potentiate their responses to aggressor cues. After defeat, strong aggressor-induced aVMHvlOXTR cell activation drives the animal to avoid the aggressor and minimizes future defeat. Our study uncovers a neural process that supports rapid social learning caused by defeat and highlights the importance of the brain oxytocin system in social plasticity.
Subject(s)
Aggression , Avoidance Learning , Hypothalamus , Neural Pathways , Neurons , Oxytocin , Social Learning , Animals , Mice , Aggression/physiology , Avoidance Learning/physiology , Cues , Fear/physiology , Hypothalamus/cytology , Hypothalamus/metabolism , Neural Pathways/physiology , Neurons/metabolism , Oxytocin/metabolism , Receptors, Oxytocin/metabolism , Social Behavior , Social Learning/physiology , Supraoptic Nucleus/cytology , Supraoptic Nucleus/metabolism , Ventromedial Hypothalamic Nucleus/cytology , Ventromedial Hypothalamic Nucleus/metabolism , Neuronal PlasticityABSTRACT
The current study was designed to examine the role of glutamate NMDA receptors of the mediodorsal thalamus (MD) in scopolamine-induced memory impairment. Adult male rats were bilaterally cannulated into the MD. According to the results, intraperitoneal (i.p.) administration of scopolamine (1.5 mg/kg) immediately after the training phase (post-training) impaired memory consolidation. Bilateral microinjection of the glutamate NMDA receptors agonist, N-Methyl-D-aspartic acid (NMDA; 0.05 µg/rat), into the MD significantly improved scopolamine-induced memory consolidation impairment. Co-administration of D-AP5, a glutamate NMDA receptor antagonist (0.001-0.005 µg/rat, intra-MD) potentiated the response of an ineffective dose of scopolamine (0.5 mg/kg, i.p.) to impair memory consolidation, mimicking the response of a higher dose of scopolamine. Noteworthy, post-training intra-MD microinjections of the same doses of NMDA or D-AP5 alone had no effect on memory consolidation. Moreover, the blockade of the glutamate NMDA receptors by 0.003 ng/rat of D-AP5 prevented the improving effect of NMDA on scopolamine-induced amnesia. Thus, it can be concluded that the MD glutamatergic system may be involved in scopolamine-induced memory impairment via the NMDA receptor signaling pathway.
Subject(s)
N-Methylaspartate , Scopolamine , Rats , Male , Animals , Scopolamine/pharmacology , N-Methylaspartate/pharmacology , Receptors, N-Methyl-D-Aspartate/metabolism , Glutamic Acid/metabolism , Rats, Wistar , Amnesia/chemically induced , Memory Disorders/chemically induced , Excitatory Amino Acid Agonists/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Thalamus/metabolism , Avoidance LearningABSTRACT
Reinforcement-based adaptive decision-making is believed to recruit fronto-striatal circuits. A critical node of the fronto-striatal circuit is the thalamus. However, direct evidence of its involvement in human reinforcement learning is lacking. We address this gap by analyzing intra-thalamic electrophysiological recordings from eight participants while they performed a reinforcement learning task. We found that in both the anterior thalamus (ATN) and dorsomedial thalamus (DMTN), low frequency oscillations (LFO, 4-12 Hz) correlated positively with expected value estimated from computational modeling during reward-based learning (after outcome delivery) or punishment-based learning (during the choice process). Furthermore, LFO recorded from ATN/DMTN were also negatively correlated with outcomes so that both components of reward prediction errors were signaled in the human thalamus. The observed differences in the prediction signals between rewarding and punishing conditions shed light on the neural mechanisms underlying action inhibition in punishment avoidance learning. Our results provide insight into the role of thalamus in reinforcement-based decision-making in humans.
Subject(s)
Reinforcement, Psychology , Reward , Humans , Avoidance Learning/physiology , Punishment , ThalamusABSTRACT
Recently, use of the synthetic cathinone (aka "bath salt") eutylone has risen in the United States and globally. Due to its novelty in drug markets, its affective properties remain largely uninvestigated. In this context, drugs of abuse have both rewarding and aversive effects and understanding these effects, their relative balance, and factors that impact each are important to understanding the likelihood of drug use and abuse. This investigation attempted to characterize eutylone's rewarding and aversive effects in a combined conditioned taste avoidance/place preference assay. Female Sprague-Dawley rats were given 20-min access to saccharin, injected with one of five doses of eutylone (0, 3, 10, 18, 32 mg/kg; intraperitoneally; IP), and placed on one side of a place conditioning apparatus. On the following day, subjects were given 20-min access to water, injected IP with vehicle, and placed on the other side of the apparatus. After five conditioning cycles, place preference and saccharin avoidance were assessed. Eutylone induced significant taste avoidance but did not significantly increase time spent on the drug-paired side (relative to controls). Excluding animals with high initial side preference, however, eutylone induced a preference at all doses with the high dose group displaying higher preference than controls. There was no significant correlation between eutylone's aversive and rewarding effects. These data indicate that eutylone (like other synthetic cathinones) induces both rewarding and aversive effects and highlight the need to assess the impact of various factors on its affective properties (and their balance) and on their use and abuse. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Subject(s)
Synthetic Cathinone , Taste , Humans , Rats , Animals , Female , Rats, Sprague-Dawley , Saccharin/pharmacology , Avoidance LearningABSTRACT
Este artigo tem como objetivo produzir uma análise histórica sobre as intersecções entre Psicologia e sexualidade desviantes da norma no Brasil, de fins do século XIX a meados da década de 1980. Esta temporalidade foi escolhida por abarcar o surgimento das pesquisas científicas sobre sexualidade e desvios sexuais, a consolidação dos estudos psicológicos sobre a temática e o processo mais recente de despatologização da homossexualidade. Em termos teóricos e metodológicos, foram adotados os pressupostos da História Social da Psicologia e da historiografia das homossexualidades no Brasil. Desse modo, buscou-se compreender como as ideias, concepções e práticas psicológicas foram mudando ao longo do tempo, em conexão com as transformações socioculturais e políticas que ocorreram durante o século XX. Para isto, foram utilizadas fontes primárias e secundárias de pesquisa com vistas à produção de interpretações sobre as conexões entre as ideias, os atores e os eventos narrados. Argumenta-se, ao longo do artigo, que as ideias e práticas psicológicas estão intrinsecamente conectadas aos contextos socioculturais e políticos de seu tempo, sendo os movimentos dinâmicos e os conflitos presentes nesses contextos fatores determinantes para a sua constituição.(AU)
This article aims to produce a historical analysis of the intersections between Psychology and sexualities that deviate from the norm in Brazil, from the late 19th century to the mid-1980s. This period was chosen because it encompasses the emergence of scientific research on sexuality and sexual deviations, the consolidation of psychological studies on the subject and the most recent process of de-pathologization of homosexuality. Theoretically and methodologically, the assumptions of the Social History of Psychology and the historiography of homosexualities in Brazil were adopted. Therefore, we sought to understand how psychological ideas, conceptions and practices have changed over time, in connection with the sociocultural and political transformations that occurred throughout the 20th century. For this, primary and secondary sources of research were used to produce interpretations about the connections between the ideas, the actors and the narrated events. It is argued, throughout the article, that the psychological ideas and practices are intrinsically connected to the sociocultural and political contexts of their time, being the dynamic movements and conflicts present in these contexts determining factors for their constitution.(AU)
Este artículo tiene como objetivo realizar un análisis histórico de las intersecciones entre la Psicología y las sexualidades desviadas de la norma en Brasil desde finales del siglo XIX hasta mediados de la década de 1980. Esta temporalidad fue elegida por abarcar el surgimiento de las investigaciones científicas sobre sexualidad y desvíos sexuales, la consolidación de los estudios psicológicos sobre el tema y el más reciente proceso de despatologización de la homosexualidad. En el marco teórico y metodológico, se adoptaron los presupuestos de la Historia Social de la Psicología y de la historiografía de las homosexualidades en Brasil. De esta manera, se pretende comprender cómo las ideas, concepciones y prácticas psicológicas han cambiado a lo largo del tiempo, en conexión con las transformaciones socioculturales y políticas ocurridas durante el siglo XX. Para ello, se utilizaron las fuentes de investigación primarias y secundarias con miras a generar interpretaciones sobre las conexiones entre las ideas, los actores y los eventos narrados. Se argumenta, a lo largo de este artículo, que las ideas y las prácticas psicológicas están intrínsecamente conectadas a los contextos socioculturales y políticos de su tiempo, y los movimientos dinámicos y los conflictos presentes en estos contextos fueron los factores determinantes para su constitución.(AU)
Subject(s)
Humans , Male , Female , Brazil , Homosexuality , Sexuality , History , Orgasm , Paraphilic Disorders , Pathology , Pedophilia , Personality Development , Personality Disorders , Pleasure-Pain Principle , Psychology , Psychosexual Development , Public Policy , Rationalization , Religion and Sex , Repression, Psychology , Sadism , Sex , Sexual Behavior , Disorders of Sex Development , Sex Offenses , Social Control, Formal , Social Environment , Societies , Avoidance Learning , Sublimation, Psychological , Taboo , Therapeutics , Transvestism , Unconscious, Psychology , Voyeurism , Behavior Therapy , Child Abuse, Sexual , Attitude , Homeopathic Cure , Character , Christianity , Mental Competency , Sexual Harassment , Coitus , Human Body , Homosexuality, Female , Conflict, Psychological , Community Participation , Cultural Diversity , Feminism , Heterosexuality , Neurobehavioral Manifestations , Sexual Dysfunctions, Psychological , Crime , Cultural Characteristics , Culture , Safe Sex , Mind-Body Therapies , Defense Mechanisms , Dehumanization , Human Characteristics , Intention , Moral Development , Emotions , Health Research Agenda , Discussion Forums , Population Studies in Public Health , Eugenics , Exhibitionism , Pleasure , Fetishism, Psychiatric , Sexual Health , Homophobia , Racism , Social Marginalization , Medicalization , Transgender Persons , Moral Status , Sexual and Gender Minorities , Political Activism , Gender Diversity , Asexuality , Undisclosed Sexuality , Sexuality Disclosure , Gender Norms , Gender Blind , Androcentrism , Freedom , Freudian Theory , Respect , Gender Identity , Sexual Trauma , Workhouses , Psychosocial Functioning , Gender Role , Intersectional Framework , Family Structure , Health Promotion , Human Development , Human Rights , Identification, Psychological , Anatomy , Disruptive, Impulse Control, and Conduct Disorders , Incest , Instinct , Introversion, Psychological , Libido , Masochism , Masturbation , Mental Disorders , Methods , Morale , Morals , Neurotic DisordersABSTRACT
OBJECTIVE: Alzheimer's disease (AD) is a neurological ailment that causes memory loss and impairments and is linked to a drop-in acetylcholine level. Acetylcholinesterase (AChE) inhibitors are used for the management of AD. In our ongoing research to search for natural AChE inhibitors from medicinal plants, we found that the Acorus calamus possesses memory-enhancing properties. α-Asarone is the major compound isolated from the Acorus calamus and it has neuroprotective action in animal models, nonetheless, its anticholinesterase activity in different brain regions was not fully understood. The purpose of this research was to determine the anti-amnesic and anti-cholinesterase activities of α-asarone against scopolamine-induced memory impairments in rats. MATERIALS AND METHODS: The anti-cholinesterase activity of α-asarone was determined using Ellman's method in different brain areas, such as the cortex, hippocampus, and striatum. In addition, the anti-amnesic effect of α-asarone was also investigated using elevated plus-maze, passive avoidance, and active avoidance tests. RESULTS: The effect of α-asarone on memory impairment against scopolamine-induced (1 mg/kg body weight) amnesia was evaluated. Administration of α-asarone (15 and 30 mg/kg body weight) for 14 days to rats significantly ameliorated the scopolamine-induced memory impairment as measured in the elevated plus-maze, passive avoidance, and avoidance active tests compared to the scopolamine-treated group. In this study, we also show that α-asarone treatment significantly (p<0.05) reduced brain acetylcholinesterase activity in the cortex, hippocampus, and striatum brain regions of amnesic rats. CONCLUSIONS: These results confirmed that α-asarone has anti-amnesic and anti-cholinesterase potential which may be useful for the management of AD.
Subject(s)
Allylbenzene Derivatives , Alzheimer Disease , Amnesia , Anisoles , Cholinesterase Inhibitors , Memory Disorders , Scopolamine , Acetylcholine/metabolism , Acetylcholinesterase/metabolism , Allylbenzene Derivatives/pharmacology , Alzheimer Disease/chemically induced , Alzheimer Disease/drug therapy , Amnesia/chemically induced , Amnesia/drug therapy , Animals , Anisoles/pharmacology , Avoidance Learning , Body Weight , Cholinesterase Inhibitors/pharmacology , Maze Learning , Memory Disorders/chemically induced , Memory Disorders/drug therapy , Rats , Scopolamine/adverse effectsABSTRACT
Researchers have begun to direct their research to focus on the use of taurine as a psychopharmacotherapeutic compound to treat a wide range of health- related conditions as well as neuropathological diseases. Moreover, taurine has been shown to improve emotional and cognitive declines associated with senescence in neurotypical animal models. However, despite these advances in the field of taurine therapeutics, much less is known regarding the effects of sex and taurine on neurotypical animal models that are then manipulated, modified, and/or mutated to study human diseases. The present study sought to investigate this matter in a Long Evans Hooded rat model of mature age (i.e., postnatal day 60-90) in an active avoidance test (AAT). Rats were trained for 20 trials, given a 1 h. test break, retrained for another 20 trials, and then tested at 24 h, 48 h, and 1 week for learning and memory retention. An N = 63 rats were randomly assigned to three groups: (1) Control (n = 22), (2) Taurine Pre-Train (n = 19), and (3) Taurine Post-Train (n = 20). The aim of the present study was to determine the effects of taurine given 15 min before training when compared to being given after training but 15 min before testing at 24 h on learning and memory consolidation of the AAT. The results showed in Control rats that females had shorter latencies to cross in the shuttle box, increased rates of correct learning by the % Avoids/Escapes, and decreased rates of learning errors by the % Shocks. In Taurine Post-Train male rats, taurine treatment decreased their latency to cross in the shuttle box and their rate of learning errors by the % Shocks at 24 h and 48 h Testing, but it had no effect on their rate of correct learning by the % Avoids/Escapes when compared to Control and Taurine Pre-Train male rats. In contrast, Taurine Post-Train female rats increased their latency to cross in the shuttle box during Training, 24 h and 48 h Testing, when compared to the Control and Taurine Pre-Train female rats. Further, Taurine Post-Train female rats decreased their rate of learning % Avoids/Escapes and increased the rate of learning errors % Shocks when compared to Control female rats during Training and 24 h Testing but decreased their rate of learning % Avoids/Escapes and increased the rate of learning errors % Shocks when compared to Taurine Pre-Train female rats across all test conditions. These findings suggest that neurotypical female rats may be more sensitive to the aversive stimuli (i.e., foot shocks) used in the AAT as a motivating factor for learning that may cause paradoxical behavioral learning and memory patterns. This phenomenon raises an important concern for researchers to consider when studying learning and behavioral tests in rodents that use aversive and non-aversive stimuli or a combination of both such as in the AAT. Taurine, albeit neuroprotective, may not have as much benefit in a neurotypical animal model and may increase the susceptibility for anxiogenic behaviors and interfere with cognitive learning and memory behaviors. Therefore, the mechanistic way(s) in which taurine can treat, recovery, ameliorate, and forestall other neuropathological diseases in animal models may have different psychopharmacodynamics and psychopharmacokinetics in a neurotypical animal model and should be studied with caution. This does not preclude the continued investigation of taurine psychopharmacotherapies for neuropathological diseases but encourages the careful investigation of taurine supplementation and treatment in neurotypical animals as paradoxical behavioral and cognitive outcomes have been observed herein.
Subject(s)
Avoidance Learning , Taurine , Animals , Emotions , Female , Humans , Male , Memory , Rats , Rats, Long-Evans , Taurine/pharmacologyABSTRACT
Tomato cultivation is threatened by the infestation of the nocturnal invasive tomato pinworm, Tuta absoluta. This study was based on field observations that a wild tomato plant, Solanum lycopersicum var. cerasiforme, grown in the Mount Kenya region, Kenya, is less attacked by T. absoluta, unlike the cultivated tomato plants like S. lycopersicum (var. Rambo F1). We hypothesized that the wild tomato plant may be actively avoided by gravid T. absoluta females because of the emission of repellent allelochemical constituents. Therefore, we compared infestation levels by the pest in field monocrops and intercrops of the two tomato genotypes, characterized the headspace volatiles, then determined the compounds detectable by the insect through gas chromatography-linked electroantennography (GC-EAG), and finally performed bioassays using a blend of four EAG-active compounds unique to the wild tomato. We found significant reductions in infestation levels in the monocrop of the wild tomato, and intercrops of wild and cultivated tomato plants compared to the monocrop of the cultivated tomato plant. Quantitative and qualitative differences were noted between volatiles of the wild and cultivated tomato plants, and between day and night volatile collections. The most discriminating compounds between the volatile treatments varied with the variable selection or machine learning methods used. In GC-EAG recordings, 16 compounds including hexanal, (Z)-3-hexenol, α-pinene, ß-myrcene, α-phellandrene, ß-phellandrene, (E)-ß-ocimene, terpinolene, limonene oxide, camphor, citronellal, methyl salicylate, (E)-ß-caryophyllene, and others tentatively identified as 3,7,7-Trimethyl-1,3,5-cycloheptatriene, germacrene D and cis-carvenone oxide were detected by antennae of T. absoluta females. Among these EAG-active compounds, (Z)-3-hexenol, α-pinene, α-phellandrene, limonene oxide, camphor, citronellal, (E)-ß-caryophyllene and ß-phellandrene are in the top 5 discriminating compounds highlighted by the machine learning methods. A blend of (Z)-3-hexenol, camphor, citronellal and limonene oxide detected only in the wild tomato showed dose-dependent repellence to T. absoluta females in wind tunnel. This study provides some groundwork for exploiting the allelochemicals of the wild tomato in the development of novel integrated pest management approaches against T. absoluta.
Subject(s)
Lepidoptera , Solanum lycopersicum , Solanum , Volatile Organic Compounds , Animals , Avoidance Learning , Camphor , Female , Solanum lycopersicum/chemistry , Machine Learning , Pheromones , Plants , Volatile Organic Compounds/chemistryABSTRACT
Scoparone (6,7-dimethoxycoumarin) is a simple coumarin from botanical drugs of Artemisia species used in Traditional Chinese Medicine and Génépi liquor. However, its bioavailability to the brain and potential central effects remain unexplored. We profiled the neuropharmacological effects of scoparone upon acute and subchronic intraperitoneal administration (2.5-25 mg/kg) in Swiss mice and determined its brain concentrations and its effects on the endocannabinoid system (ECS) and related lipids using LC-ESI-MS/MS. Scoparone showed no effect in the forced swimming test (FST) but, administered acutely, led to a bell-shaped anxiogenic-like behavior in the elevated plus-maze test and bell-shaped procognitive effects in the passive avoidance test when given subchronically and acutely. Scoparone rapidly but moderately accumulated in the brain (Cmax < 15 min) with an apparent first-order elimination (95% eliminated at 1 h). Acute scoparone administration (5 mg/kg) significantly increased brain arachidonic acid, prostaglandins, and N-acylethanolamines (NAEs) in the FST. Conversely, subchronic scoparone treatment (2.5 mg/kg) decreased NAEs and increased 2-arachidonoylglycerol. Scoparone differentially impacted ECS lipid remodeling in the brain independent of serine hydrolase modulation. Overall, the unexpectedly potent central effects of scoparone observed in mice could have toxicopharmacological implications for humans.
Subject(s)
Brain/metabolism , Coumarins/pharmacology , Animals , Arachidonic Acid/metabolism , Arachidonic Acids/metabolism , Avoidance Learning/drug effects , Behavior, Animal/drug effects , Biological Availability , Cognition/drug effects , Coumarins/administration & dosage , Coumarins/pharmacokinetics , Endocannabinoids/metabolism , Ethanolamines/metabolism , Glycerides/metabolism , Infusions, Parenteral , Lipid Metabolism , Male , Maze Learning/drug effects , Mice , Prostaglandins/metabolismABSTRACT
Objective: While stress reportedly impairs memory, saffron enhances it. This study investigated the therapeutic effects of saffron extract on different memory types, anxiety-like behavior, and expressions of BDNF and TNF-α genes in sub-chronically stressed rats.Methods: Rats were randomly assigned to control, restraint stress (6â h/day/7 days), two 7-days saffron treatments with 30 and 60â mg/kg, and two stress-saffron groups (30 and 60â mg/kg/7 post-stress days). Serum cortisol level and hippocampal BDNF and TNF-α gene expressions were measured. Open field, passive avoidance, novel object recognition, and object location tests were performed to assess anxiety-like behavior and avoidance as well as cognitive and spatial memories, respectively.Results: The low saffron dose in the sub-chronic stressed group led to a significant increase in passive avoidance latency from day 3 onward whereas this effect was observed after 7 days under the high-dose treatment that simultaneously led to a significant decline in serum cortisol level. While the low saffron dose led to a sharp drop in hippocampal TNF-α gene expression, the high dose significantly increased the hippocampal BDNF gene expression in the sub-chronic stress group. Finally, both saffron doses reduced anxiety in the stressed groups.Conclusion: Compared to the low saffron dose, the high dose had a latent but long-lasting impact. Cognitive and spatial memories remained unaffected by either stress or saffron treatment. In addition, only the high saffron dose reversed anxiety in the sub-chronically stressed group. These findings suggest that various doses of saffron act differently on different brain functions under sub-chronic stress conditions.Abbreviations: Brain derived neurotrophic factor (BDNF), tumor necrosis factor-α (TNF-α), hypothalamic-pituitary-adrenal axis (HPA), novel object recognition task (NORT), novel object location task (NOLT), open field test (OFT), passive avoidance (PA).
Subject(s)
Anxiety/drug therapy , Brain-Derived Neurotrophic Factor/genetics , Crocus/chemistry , Plant Extracts/administration & dosage , Stress, Psychological/physiopathology , Tumor Necrosis Factor-alpha/genetics , Animals , Avoidance Learning/drug effects , Behavior, Animal/drug effects , Brain/drug effects , Brain/physiopathology , Dose-Response Relationship, Drug , Gene Expression/drug effects , Hippocampus/metabolism , Male , Memory/drug effects , Phytotherapy , Rats , Restraint, Physical , Stress, Psychological/psychologyABSTRACT
Depressive anxiety is one of the most emotional disorders in our industrial societies. Many treatments of phobias exist and are based on plant extracts therapies, which play an important role in the amelioration of the behavior. Our study aimed to evaluate the adaptogenic activity of different essential oils provided from local plants: Cinnamomum camphora (Camphora), Eucalyptus globulus (Blue gum), Lavandula stÅchas (Topped lavender) and Rosmarinus officinalis (Rosemary) on Wistar rats. The adaptogenic activity was evaluated on the elevated plus-maze. The efficacy of the extract (200 mL/kg) was compared with the standard anxiolytic drug Diazepam® 1 mg. Animals administered by the essential oil of Lavandula stÅchas, Cinnamomum camphora, Rosmarinus officinalis and Eucalyptus globulus showed a behavior similar to those treated with Diazepam®. For groups treated with the following essential oils: Rosmarinus officinalis, Lavandula stoechas and Cinnamomum camphora at a dose of 200 mL/kg, we notice an increase in the time spent on the open arms of the elevated plus-maze and a decrease in time spent on the closed arms of the elevated plus-maze, especially for Rosmarinus officinalis, which explains the anxiolytic effect of these plants. We also notice a decrease in the number of entries in closed arms, open arms and the number of passing to the central square. The increase in the number of entries to open arms with Eucalyptus globulus essential oil shows a reduction in anxiety behavior in rodents and this shows that these plants have an inhibitory effect.
Subject(s)
Cinnamomum camphora/chemistry , Eucalyptus/chemistry , Lavandula/chemistry , Medicine, Traditional/methods , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Rosmarinus/chemistry , Africa, Northern , Animals , Anxiety/physiopathology , Anxiety/prevention & control , Avoidance Learning/drug effects , Avoidance Learning/physiology , Humans , Maze Learning/drug effects , Maze Learning/physiology , Oils, Volatile/isolation & purification , Plant Oils/isolation & purification , Rats, WistarABSTRACT
Innately aversive experiences produce rapid defensive responses and powerful emotional memories. The midbrain periaqueductal gray (PAG) drives defensive behaviors through projections to brainstem motor control centers, but the PAG has also been implicated in aversive learning, receives information from aversive-signaling sensory systems and sends ascending projections to the thalamus as well as other forebrain structures which could control learning and memory. Here we sought to identify PAG subregions and cell types which instruct memory formation in response to aversive events. We found that optogenetic inhibition of neurons in the dorsolateral subregion of the PAG (dlPAG), but not the ventrolateral PAG (vlPAG), during an aversive event reduced memory formation. Furthermore, inhibition of a specific population of thalamus projecting dlPAG neurons projecting to the anterior paraventricular thalamus (aPVT) reduced aversive learning, but had no effect on the expression of previously learned defensive behaviors. By contrast, inactivation of dlPAG neurons which project to the posterior PVT (pPVT) or centromedial intralaminar thalamic nucleus (CM) had no effect on learning. These results reveal specific subregions and cell types within PAG responsible for its learning related functions.
Subject(s)
Avoidance Learning/physiology , Acoustic Stimulation , Animals , Brain Mapping , Conditioning, Classical/physiology , Cues , Electroshock , Fear/physiology , Freezing Reaction, Cataleptic/physiology , Male , Neural Pathways/physiology , Neurons/physiology , Optogenetics , Periaqueductal Gray/physiology , Rats , Rats, Sprague-Dawley , Thalamus/physiologyABSTRACT
Bed nucleus of the stria terminalis (BNST) neurons that synthesize corticotropin-releasing factor (CRF) drive binge alcohol drinking and anxiety. Here, we found that female C57BL/6J mice binge drink more than males and have greater basal BNSTCRF neuron excitability and synaptic excitation. We identified a dense VGLUT2 + synaptic input from the paraventricular thalamus (PVT) that releases glutamate directly onto BNSTCRF neurons but also engages a large BNST interneuron population to ultimately inhibit BNSTCRF neurons, and this polysynaptic PVTVGLUT2-BNSTCRF circuit is more robust in females than males. Chemogenetic inhibition of the PVTBNST projection promoted binge alcohol drinking only in female mice, while activation reduced avoidance behavior in both sexes. Lastly, repeated binge drinking produced a female-like phenotype in the male PVT-BNSTCRF excitatory synapse without altering the function of PVTBNST neurons per se. Our data describe a complex, feedforward inhibitory PVTVGLUT2-BNSTCRF circuit that is sex-dependent in its function, behavioral roles, and alcohol-induced plasticity.
Subject(s)
Alcohol Drinking/pathology , Avoidance Learning , Corticotropin-Releasing Hormone/metabolism , Limbic System/pathology , Neurons/pathology , Synapses/pathology , Thalamus/pathology , Alcohol Drinking/physiopathology , Animals , Anxiety/physiopathology , Behavior, Animal , Excitatory Postsynaptic Potentials , Female , Glutamic Acid/metabolism , Inhibitory Postsynaptic Potentials , Integrases/metabolism , Limbic System/physiopathology , Male , Mice, Inbred C57BL , Phenotype , Septal Nuclei/pathology , Septal Nuclei/physiopathology , Sex Characteristics , Thalamus/physiopathologyABSTRACT
OBJECTIVE: Alzheimer's disease is a progressive, age-related, and neurodegenerative disease characterized by mental decline. The exact cause of Alzheimer's disease is unclear, but cholinergic dysfunction, protein accumulation, and oxidative stress are among the most important hypotheses. The main purpose of our study was to investigate the effects of aqueous and hydroalcoholic extract combination of these two medicinal plants, black pepper and cumin (as a related formulation in traditional Persian medicine), on memory and learning of an immobilized stress animal model. METHODS: In this study, hydroalcoholic and aqueous extracts of cumin and black pepper fruits were prepared. Six groups of mice were treated orally for 2 weeks: control group, immobility stress, and stress-induced immobility mice received different doses of the hydroalcoholic extract (100 and 200 mg/kg) and aqueous extract (100 and 200 mg/kg). The shuttle box, novel object detection, and rotarod test were used to evaluate memory and learning. The activities of acetylcholinesterase, catalase (CAT), and superoxide dismutase (SOD) and the level of reduced glutathione (GSH) and malondialdehyde (MDA) were measured in the brain tissue. RESULTS: Immobility stress significantly reduced learning and motor coordination. Furthermore, MDA levels and acetylcholinesterase activity were significantly increased, while CAT and SOD activities were significantly reduced in the brain of immobility-induced stress mice. Other findings indicated that hydroalcoholic and aqueous extracts (100 and 200 mg/kg) of cumin and black pepper fruits have an improving effect on animal motor coordination and learning ability, GSH content, and CAT, SOD, and acetylcholinesterase enzyme function in comparison with stress groups (p < 0.05). CONCLUSION: The hydroalcoholic and aqueous extracts of cumin and black pepper fruits have protective effects against stress-induced memory deficit and oxidative stress and may have beneficial therapeutic effect in the treatment of neurodegenerative diseases.
Subject(s)
Alzheimer Disease/drug therapy , Apiaceae/metabolism , Memory Disorders/drug therapy , Piper nigrum/metabolism , Acetylcholinesterase/metabolism , Alcohols/chemistry , Animals , Avoidance Learning , Capsicum/chemistry , Catalase/metabolism , Cuminum/chemistry , Disease Models, Animal , Glutathione/metabolism , Immobilization , Iran , Lipid Peroxidation , Medicine, Traditional , Mice , Oxidative Stress , Plant Extracts/pharmacology , Stress, Mechanical , Stress, Psychological , Superoxide Dismutase/metabolismABSTRACT
Successful responding to acutely threatening situations requires adequate approach-avoidance decisions. However, it is unclear how threat-induced states-like freezing-related bradycardia-impact the weighing of the potential outcomes of such value-based decisions. Insight into the underlying computations is essential, not only to improve our models of decision-making but also to improve interventions for maladaptive decisions, for instance in anxiety patients and first-responders who frequently have to make decisions under acute threat. Forty-two participants made passive and active approach-avoidance decisions under threat-of-shock when confronted with mixed outcome-prospects (i.e., varying money and shock amounts). Choice behavior was best predicted by a model including individual action-tendencies and bradycardia, beyond the subjective value of the outcome. Moreover, threat-related bradycardia (high-vs-low threat) interacted with subjective value, depending on the action-context (passive-vs-active). Specifically, in action-contexts incongruent with participants' intrinsic action-tendencies, stronger bradycardia related to diminished effects of subjective value on choice across participants. These findings illustrate the relevance of testing approach-avoidance decisions in relatively ecologically valid conditions of acute and primarily reinforced threat. These mechanistic insights into approach-avoidance conflict-resolution may inspire biofeedback-related techniques to optimize decision-making under threat. Critically, the findings demonstrate the relevance of incorporating internal psychophysiological states and external action-contexts into models of approach-avoidance decision-making.
Subject(s)
Avoidance Learning/physiology , Decision Making/physiology , Freezing , Hippocampus/physiology , Adolescent , Adult , Anxiety , Autonomic Nervous System , Biofeedback, Psychology , Bradycardia , Choice Behavior , Conflict, Psychological , Emotions , Female , Humans , Learning , Male , Negotiating , Psychophysiology , Reinforcement, Psychology , Sensitivity and Specificity , Young AdultABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Diabetes is a systemic disease, which can cause synaptic defects in the hippocampus. Hippocampus plays a crucial role in learning and memory. Melissa officinalis L. has been used as for memory enhancement in Persian Medicine. AIM OF THE STUDY: The aim of this study was to evaluate the impact of the hydroalcoholic extract of Melissa officinalis L. on learning and memory, considering its impact on nitric oxide synthase and brain-derived neurotrophic factor expression in the hippocampus of diabetic rats. MATERIALS AND METHODS: Melissa officinalis L. extract was obtained by maceration method. To evaluate phenolic and flavonoid compounds of the extract, the samples were analyzed by HPLC. The animals were randomly divided into 6 groups: vehicle-treated control, Melissa officinalis-treated control (50 mg/kg), vehicle-treated diabetic, and M. officinalis-treated diabetic (25, 50, or 100 mg/kg). Diabetes was induced by streptozotocin And Melissa officinalis L. was administered for 2 weeks once diabetes was induced. Passive avoidance and Y-maze tasks were performed for learning and memory assessment. At the end of learning and memory tasks, rats were sacrificed and their hippocampus removed, lysed, and homogenized. The RNA contents were purified and then used as the template for cDNA synthesis. Real-time PCR was used to evaluate nitric oxide synthase and brain-derived neurotrophic factor genes expression. RESULTS: Rutin was main flavonoid compound and rosmarinic acid was the main phenolic compound of the Melissa officinalis extract. Streptozotocin induced diabetes and impaired learning and memory in diabetic rats. Melissa officinalis treated-control group showed a higher alternation score in the Y-maze task and step-through latency in the passive avoidance task compared to the vehicle treated diabetic group. Melissa officinalis-treated rats showed a higher alternation score in the Y-maze task in all doses compared to the vehicle treated diabetic group (P < 0.05). In addition, in the passive avoidance task Melissa officinalis increased step-through latency (P < 0.05) but not initial latency, in all doses. Furthermore, in diabetic rats, the expression of brain-derived neurotrophic factor and nitric oxide synthase genes decreased. However, hippocampal brain-derived neurotrophic factor and nitric oxide synthase gene expression was increased in Melissa officinalis-treated rats compared to diabetic rats (P < 0.05). CONCLUSIONS: Melissa officinalis improved learning and memory in diabetic rats, which may have occurred by increasing brain-derived neurotrophic factor and nitric oxide synthase gene expression.
Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , Diabetes Mellitus, Experimental/metabolism , Hippocampus/metabolism , Melissa/chemistry , Nitric Oxide Synthase Type III/metabolism , Plant Extracts/pharmacology , Animals , Avoidance Learning/drug effects , Behavior, Animal/drug effects , Blood Glucose/drug effects , Body Weight/drug effects , Cognition Disorders/etiology , Cognition Disorders/prevention & control , Diabetes Mellitus, Experimental/complications , Hippocampus/drug effects , Learning/drug effects , Male , Memory/drug effects , Plant Extracts/therapeutic use , Rats, Wistar , StreptozocinABSTRACT
Survival depends on a balance between seeking rewards and avoiding potential threats, but the neural circuits that regulate this motivational conflict remain largely unknown. Using an approach-food vs. avoid-predator threat conflict test in rats, we identified a subpopulation of neurons in the anterior portion of the paraventricular thalamic nucleus (aPVT) which express corticotrophin-releasing factor (CRF) and are preferentially recruited during conflict. Inactivation of aPVTCRF neurons during conflict biases animal's response toward food, whereas activation of these cells recapitulates the food-seeking suppression observed during conflict. aPVTCRF neurons project densely to the nucleus accumbens (NAc), and activity in this pathway reduces food seeking and increases avoidance. In addition, we identified the ventromedial hypothalamus (VMH) as a critical input to aPVTCRF neurons, and demonstrated that VMH-aPVT neurons mediate defensive behaviors exclusively during conflict. Together, our findings describe a hypothalamic-thalamostriatal circuit that suppresses reward-seeking behavior under the competing demands of avoiding threats.
Subject(s)
Avoidance Learning/physiology , Corticotropin-Releasing Hormone/metabolism , Hypothalamus/physiology , Midline Thalamic Nuclei/metabolism , Nerve Net/physiology , Neurons/metabolism , Ventromedial Hypothalamic Nucleus/physiology , Animals , Behavior Rating Scale , Conflict, Psychological , Female , Hypothalamus/metabolism , Male , Midline Thalamic Nuclei/cytology , Midline Thalamic Nuclei/drug effects , Midline Thalamic Nuclei/radiation effects , Neurons/drug effects , Nucleus Accumbens/metabolism , Nucleus Accumbens/physiology , Nucleus Accumbens/radiation effects , Optogenetics , Proto-Oncogene Proteins c-fos/metabolism , Rats , Reward , Ventromedial Hypothalamic Nucleus/cytologyABSTRACT
Individuals experiencing avoidant personality disorder (AvPD) tend to make sense of social interactions via maladaptive self-and other attributions. They also experience difficulties in recognizing emotions. A further feature of AvPD psychopathology is the tendency to resort to maladaptive coping strategies, such as behavioral avoidance and perfectionism. Despite its impact, psychological treatments for AvPD remains poorly investigated. Herein, we describe the first five sessions of Metacognitive Interpersonal Therapy with a 28-year-old woman, whose treatment goal was to reduce social avoidance. We describe how this goal was achieved through a combination of working through the therapeutic relationship, alongside experiential techniques such as guided imagery, rescripting, and bodily work. Through this treatment configuration, the patient was able to increase self-awareness of her own emotions, enabling her to realize that she was guided by rigid schemas; specifically seeing herself as inadequate and others as judgmental. Finally, implications for the treatment of AvPD are discussed.
Subject(s)
Personality Disorders/psychology , Personality Disorders/therapy , Psychotherapy , Therapeutic Alliance , Adult , Avoidance Learning , Emotions , Female , Humans , PerfectionismABSTRACT
Animals, including humans, readily learn to avoid harmful and threatening situations by moving in response to cues that predict the threat (e.g., fire alarm, traffic light). During a negatively reinforced sensory-guided locomotor action, known as signaled active avoidance, animals learn to avoid a harmful unconditioned stimulus (US) by moving away when signaled by a harmless conditioned stimulus (CS) that predicts the threat. CaMKII-expressing neurons in the pedunculopontine tegmentum area (PPT) of the midbrain locomotor region have been shown to play a critical role in the expression of this learned behavior, but the activity of these neurons during learned behavior is unknown. Using calcium imaging fiber photometry in freely behaving mice, we show that PPT neurons sharply activate during presentation of the auditory CS that predicts the threat before onset of avoidance movement. PPT neurons activate further during the succeeding CS-driven avoidance movement, or during the faster US-driven escape movement. PPT neuron activation was weak during slow spontaneous movements but correlated sharply with movement speed and, therefore, with the urgency of the behavior. Moreover, using optogenetics, we found that these neurons must discharge during the signaled avoidance interval for naive mice to effectively learn the active avoidance behavior. As an essential hub for signaled active avoidance, neurons in the midbrain tegmentum process the conditioned cue that predicts the threat and discharge sharply relative to the speed or apparent urgency of the avoidance (learned) and escape (innate) responses.SIGNIFICANCE STATEMENT During signaled active avoidance behavior, subjects move away to avoid a threat when directed by an innocuous sensory stimulus. Using imaging methods in freely behaving mice, we found that the activity of neurons in a part of the midbrain, known as the pedunculopontime tegmentum, increases during the presentation of the innocuous sensory stimulus that predicts the threat and also during the expression of the learned behavior as mice move away to avoid the threat. In addition, inhibiting these neurons abolishes the ability of mice to learn the behavior. Thus, neurons in this part of the midbrain code and are essential for signaled active avoidance behavior.
Subject(s)
Avoidance Learning/physiology , Locomotion/physiology , Tegmentum Mesencephali/physiology , Acoustic Stimulation , Animals , Cues , Escape Reaction/physiology , Mice , Mice, Inbred C57BL , Neuroimaging , Neurons/physiology , Optogenetics , Pedunculopontine Tegmental Nucleus/physiology , PhotometryABSTRACT
Alzheimer's disease is the most common neurodegenerative disease associated with deposition of amyloid-beta and the increased oxidative stress. High free radical scavenging ability of selenium nanoparticles (SeNPs) has been acknowledged, so in the present study, the effects of treatment with SeNPs on Streptozotocin (STZ)-induced neurotoxicity were evaluated in the male rats. Learning and memory impairment was induced by intraventricular injection of STZ. Following induction of memory impairment, the rats received 0.4 mg/kg of SeNPs daily for one month. Memory function, antioxidant capacity, and deposition of Amyloid ß (Aß) were assessed using the shuttle box task, biochemical methods, and Congo red staining. Injection of STZ caused memory impairment, a decrease in the level of total thiol group (TTG), and an increase in the malondialdehyde (MDA) content and deposition of Aß. Administration of SeNPs reversed the neurotoxicity induced by STZ. It seems that SeNPs likely had neuroprotective effects on the animal model of Alzheimer's disease through increasing antioxidantsÒ capacity.