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1.
Sci Rep ; 13(1): 3113, 2023 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-36813823

RESUMO

Possible interactions of the neuropeptide oxytocin and the sex hormone estradiol may contribute to previously observed sex-specific effects of oxytocin on resting-state functional connectivity (rsFC) of the amygdala and hippocampus. Therefore, we used a placebo-controlled, randomized, parallel-group functional magnetic resonance imaging study design and measured amygdala and hippocampus rsFC in healthy men (n = 116) and free-cycling women (n = 111), who received estradiol gel (2 mg) or placebo before the intranasal administration of oxytocin (24 IU) or placebo. Our results reveal significant interaction effects of sex and treatments on rsFC of the amygdala and hippocampus in a seed-to-voxel analysis. In men, both oxytocin and estradiol significantly decreased rsFC between the left amygdala and the right and left lingual gyrus, the right calcarine fissure, and the right superior parietal gyrus compared to placebo, while the combined treatment produced a significant increase in rsFC. In women, the single treatments significantly increased the rsFC between the right hippocampus and the left anterior cingulate gyrus, whereas the combined treatment had the opposite effect. Collectively, our study indicates that exogenous oxytocin and estradiol have different region-specific effects on rsFC in women and men and that the combined treatment may produce antagonistic effects.


Assuntos
Estradiol , Ocitocina , Masculino , Humanos , Feminino , Ocitocina/farmacologia , Estradiol/farmacologia , Giro do Cíngulo , Tonsila do Cerebelo , Hipocampo , Imageamento por Ressonância Magnética/métodos
2.
Neuroimage ; 264: 119689, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36349596

RESUMO

Considerable evidence supports sex differences in episodic memory. The hormones estradiol and oxytocin both affect episodic memory and may contribute to these sex differences, but possible underlying hormonal interactions have not been tested in a sample involving both sexes. To this end, we conducted a randomized, placebo-controlled, parallel-group functional magnetic resonance imaging (fMRI) study including healthy free-cycling women (n = 111) and men (n = 115). The fMRI session was conducted under four experimental conditions: 1. transdermal estradiol (2 mg) and intranasal oxytocin (24 IU), 2. transdermal placebo and intranasal oxytocin, 3. transdermal estradiol and intranasal placebo, 4. transdermal placebo and intranasal placebo. Participants were scanned during the encoding of positive, neutral, and negative scenes. Recognition memory was tested three days following the scanning sessions without additional treatments. Under placebo, women showed a significantly better recognition memory and increased hippocampal responses to subsequently remembered items independent of the emotional valence compared to men. The separate treatments with either hormone significantly diminished this mnemonic sex difference and reversed the hippocampal activation pattern. However, the combined treatments produced no significant effect. Collectively, the results suggest that both hormones play a crucial role in modulating sex differences in episodic memory. Furthermore, possible antagonistic interactions between estradiol and oxytocin could explain previously observed opposing hormonal effects in women and men.


Assuntos
Memória Episódica , Ocitocina , Feminino , Humanos , Masculino , Ocitocina/farmacologia , Caracteres Sexuais , Estradiol/farmacologia , Emoções/fisiologia , Administração Intranasal , Imageamento por Ressonância Magnética , Método Duplo-Cego
3.
Healthcare (Basel) ; 10(10)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36292361

RESUMO

Background: The early COVID-19-pandemic was characterized by changes in decision making, decision-relevant value systems and the related perception of decisional uncertainties and conflicts resulting in decisional burden and stress. The vulnerability of clinical care professionals to these decisional dilemmas has not been characterized yet. Methods: A cross-sectional questionnaire study (540 patients, 322 physicians and 369 nurses in 11 institutions throughout Germany) was carried out. The inclusion criterion was active involvement in clinical treatment or decision making in oncology or psychiatry during the first year of COVID-19. The questionnaires covered five decision dimensions (conflicts and uncertainty, resources, risk perception, perception of consequences for clinical processes, and the perception of consequences for patients). Data analysis was performed using ANOVA, Pearson rank correlations, and the Chi²-test, and for inferential analysis, nominal logistic regression and tree classification were conducted. Results: Professionals reported changes in clinical management (27.5%) and a higher workload (29.2%), resulting in decisional uncertainty (19.2%) and decisional conflicts (22.7%), with significant differences between professional groups (p < 0.005), including anxiety, depression, loneliness and stress in professional subgroups (p < 0.001). Nominal regression analysis targeting "Decisional Uncertainty" provided a highly significant prediction model (LQ p < 0.001) containing eight variables, and the analysis for "Decisional Conflicts" included six items. The classification rates were 64.4% and 92.7%, respectively. Tree analysis confirmed three levels of determinants. Conclusions: Decisional uncertainty and conflicts during the COVID-19 pandemic were independent of the actual pandemic load. Vulnerable professional groups for the perception of a high number of decisional dilemmas were characterized by individual perception and the psychological framework. Coping and management strategies should target vulnerability, enable the handling of the individual perception of decisional dilemmas and ensure information availability and specific support for younger professionals.

4.
Cancers (Basel) ; 14(17)2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36077852

RESUMO

Background: Pandemics are related to changes in clinical management. Factors that are associated with individual perceptions of related risks and decision-making processes focused on prevention and vaccination, but perceptions of other healthcare consequences are less investigated. Different perceptions of patients, nurses, and physicians on consequences regarding clinical management, decisional criteria, and burden were compared. Study Design: Cross-sectional OnCoVID questionnaire studies. Methods: Data that involved 1231 patients, physicians, and nurses from 11 German institutions that were actively involved in clinical treatment or decision-making in oncology or psychiatry were collected. Multivariate statistical approaches were used to analyze the stakeholder comparisons. Results: A total of 29.2% of professionals reported extensive changes in workload. Professionals in psychiatry returned severe impact of pandemic on all major aspects of their clinical care, but less changes were reported in oncology (p < 0.001). Both patient groups reported much lower recognition of treatment modifications and consequences for their own care. Decisional and pandemic burden was intensively attributed from professionals towards patients, but less in the opposite direction. Conclusions: All of the groups share concerns about the impact of the COVID-19 pandemic on healthcare management and clinical processes, but to very different extent. The perception of changes is dissociated in projection towards other stakeholders. Specific awareness should avoid the dissociated impact perception between patients and professionals potentially resulting in impaired shared decision-making.

5.
Healthcare (Basel) ; 10(6)2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35742070

RESUMO

(1) Background: Uncertainty is typical for a pandemic or similar healthcare crisis. This affects patients with resulting decisional conflicts and disturbed shared decision making during their treatment occurring to a very different extent. Sociodemographic factors and the individual perception of pandemic-related problems likely determine this decisional dilemma for patients and can characterize vulnerable groups with special susceptibility for decisional problems and related consequences. (2) Methods: Cross-sectional data from the OnCoVID questionnaire study were used involving 540 patients from 11 participating institutions covering all major regions in Germany. Participants were actively involved in clinical treatment in oncology or psychiatry during the COVID-19 pandemic. Questionnaires covered five decision dimensions (conflicts and uncertainty, resources, risk perception, perception of consequences for clinical processes, perception of consequences for patients) and very basic demographic data (age, gender, stage of treatment and educational background). Decision uncertainties and distress were operationalized using equidistant five-point scales. Data analysis was performed using descriptive and various multivariate approaches. (3) Results: A total of 11.5% of all patients described intensive uncertainty in their clinical decisions that was significantly correlated with anxiety, depression, loneliness and stress. Younger and female patients and those of higher educational status and treatment stage had the highest values for these stressors (p < 0.001). Only 15.3% of the patients (14.9% oncology, 16.2% psychiatry; p = 0.021) considered the additional risk of COVID-19 infections as very important for their disease-related decisions. Regression analysis identified determinants for patients at risk of a decisional dilemma, including information availability, educational level, age group and requirement of treatment decision making. (4) Conclusions: In patients, the COVID-19 pandemic induced specific decisional uncertainty and distress accompanied by intensified stress and psychological disturbances. Determinants of specific vulnerability were related to female sex, younger age, education level, disease stages and perception of pandemic-related treatment modifications, whereas availability of sufficient pandemic-related information prevented these problems. The most important decisional criteria for patients under these conditions were expected side effects/complications and treatment responses.

6.
Eur Neuropsychopharmacol ; 50: 46-54, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33957337

RESUMO

Burgeoning evidence indicates that women are more sensitive to the context of an offer and show a stronger propensity to adjust their behavior with changing fairness frames. We evaluated whether the sex hormone estradiol and associated stereotypical beliefs contribute to fairness framings by administering topical estradiol (2 mg) to 108 healthy women and 104 heathy men in a randomized, double-blind, placebo-controlled between-subject study design. Participants played the role of the responder in a modified version of the Ultimatum Game (UG), in which identical offers for the division of a given amount of money were framed as either fair or unfair. Furthermore, participants completed an unframed UG and a delayed discounting task to probe possible effects of estradiol on altruistic preferences and delay gratification. Our results show that women were more sensitive to fairness frames than men. Intriguingly, however, estradiol had sex-specific effects on fairness sensitivity by increasing the acceptance rate of proposals with a fair frame in men and reducing it in women. Furthermore, the mere belief of receiving estradiol treatment significantly increased the acceptance of unfair-framed offers in both sexes, but estradiol did not significantly alter the response to unframed offers and impulsive decision-making. Collectively, our findings indicate that estradiol has opposing effects on the sensitivity to the perceived fairness of economic offers in women and men. The profound effects of estradiol treatment and stereotypical beliefs provide support for the notion that sex differences in fairness framing are rooted in both biological and environmental factors.


Assuntos
Estradiol , Caracteres Sexuais , Tomada de Decisões/fisiologia , Feminino , Jogos Experimentais , Humanos , Masculino , Personalidade
7.
Expert Rev Neurother ; 20(7): 687-696, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32511043

RESUMO

INTRODUCTION: MR-guided focused ultrasound operating at higher intensities have been reported to effectively and precisely ablate deeper brain structures like the basal ganglia or the thalamic nuclei for the treatment of refractory movement disorders, neuropathic pain and most recently neuropsychiatric disorders, while low-intensity focused ultrasound represents an approach promoting mechanical blood-brain-barrier opening and neuromodulation. This narrative review summarizes the technical development and the therapeutic potential of incisionless MRgFUS in order to treat neuropsychiatric disorders. AREAS COVERED: A narrative review of clinical trials assessing the safety and efficacy of MRgFUS. A literature review was performed using the following search terms: MR-guided focused ultrasound, psychiatric disorders, noninvasive and invasive brain modulation/stimulation techniques. EXPERT OPINION: MRgFUS ablation is under clinical investigation (unblinded study design) for obsessive-compulsive disorders (OCDs) [capsulotomy; ALIC] and depression/anxiety disorders [capsulotomy] and has demonstrated an improvement in OCD and depression, although of preliminary character. Low-intensity ultrasound applications have been explored in Alzheimer´s disease (phase 1 study) and healthy subjects. Currently, limited evidence hinders comparison and selection between MRgFUS and noninvasive/invasive brain modulation therapies. However, comparative, sham-controlled trials are needed to reexamine the preliminary findings for the treatment of psychiatric disorders.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Imageamento por Ressonância Magnética , Transtornos Mentais/terapia , Cirurgia Assistida por Computador , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Ablação por Ultrassom Focalizado de Alta Intensidade/normas , Humanos , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/normas , Transtornos Mentais/diagnóstico por imagem , Transtornos Mentais/cirurgia , Cirurgia Assistida por Computador/métodos , Cirurgia Assistida por Computador/normas
8.
Int J Mol Sci ; 20(19)2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31554241

RESUMO

Chronic pain is a devastating condition affecting the physical, psychological, and socioeconomic status of the patient. Inflammation and immunometabolism play roles in the pathophysiology of chronic pain disorders. Electrical neuromodulation approaches have shown a meaningful success in otherwise drug-resistant chronic pain conditions, including failed back surgery, neuropathic pain, and migraine. A literature review (PubMed, MEDLINE/OVID, SCOPUS, and manual searches of the bibliographies of known primary and review articles) was performed using the following search terms: chronic pain disorders, systemic inflammation, immunometabolism, prediction, biomarkers, metabolic disorders, and neuromodulation for chronic pain. Experimental studies indicate a relationship between the development and maintenance of chronic pain conditions and a deteriorated immunometabolic state mediated by circulating cytokines, chemokines, and cellular components. A few uncontrolled in-human studies found increased levels of pro-inflammatory cytokines known to drive metabolic disorders in chronic pain patients undergoing neurostimulation therapies. In this narrative review, we summarize the current knowledge and possible relationships of available neurostimulation therapies for chronic pain with mediators of central and peripheral neuroinflammation and immunometabolism on a molecular level. However, to address the needs for predictive factors and biomarkers, large-scale databank driven clinical trials are needed to determine the clinical value of molecular profiling.


Assuntos
Biomarcadores , Dor Crônica/etiologia , Dor Crônica/metabolismo , Leptina/metabolismo , Redes e Vias Metabólicas , Transdução de Sinais , Animais , Dor Crônica/diagnóstico , Dor Crônica/terapia , Humanos , Mediadores da Inflamação/sangue , Mediadores da Inflamação/metabolismo , Manejo da Dor , Medição da Dor
9.
Artigo em Inglês | MEDLINE | ID: mdl-31204249

RESUMO

BACKGROUND: Animal models of addiction suggest that the transition from incentive-driven drug use to habitual and ultimately compulsive drug use is mediated by a shift from ventral to dorsal striatal cue control over drug seeking. Previous studies in human cannabis users reported elevated trait impulsivity and neural cue reactivity in striatal circuits; however, these studies were not able to separate addiction-related from exposure-related adaptations. METHODS: To differentiate the adaptive changes, the current functional magnetic resonance imaging study examined behavioral and neural cue reactivity in dependent (n = 18) and nondependent (n = 20) heavy cannabis users and a nonusing reference group (n = 44). RESULTS: Irrespective of dependence status, cannabis users demonstrated elevated trait impulsivity as well as increased ventral striatal reactivity and striatal frontal coupling in response to drug cues. Dependent users selectively exhibited dorsal striatal reactivity and decreased striatal limbic coupling during cue exposure. An exploratory analysis revealed that higher ventral caudate neural cue reactivity was associated with stronger cue-induced arousal and craving in dependent users, whereas this pattern was reversed in nondependent users. CONCLUSIONS: Taken together, the current findings suggest that exaggerated responses of the ventral striatal reward system may promote excessive drug use in humans, whereas adaptations in dorsal striatal systems engaged in habit formation may promote the transition to addictive use.


Assuntos
Núcleo Caudado/fisiopatologia , Sinais (Psicologia) , Abuso de Maconha/fisiopatologia , Fumar Maconha/fisiopatologia , Estriado Ventral/fisiopatologia , Adulto , Encéfalo/fisiopatologia , Mapeamento Encefálico , Lobo Frontal/fisiopatologia , Humanos , Comportamento Impulsivo , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiopatologia , Adulto Jovem
10.
Early Interv Psychiatry ; 13(6): 1404-1415, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30784233

RESUMO

AIM: Meta-analyses indicate positive effects of both antipsychotic and cognitive-behavioural interventions in subjects clinically at high risk (CHR) for psychosis in terms of a delay or prevention of psychotic disorders. However, these effects have been limited regarding social functioning and the relative efficacy of both types of interventions remains unclear. Furthermore, neuroprotective substances seem to be a promising alternative agent in psychosis-prevention as they are associated with few and weak side-effects. METHODS: In this multi-centre randomized controlled trial (RCT), we investigate the effects of two interventions on transition to psychosis and social functioning: (a) an integrated preventive psychological intervention (IPPI) including stress-/symptom-management and social-cognitive remediation; (b) N-acetyl-l-cysteine (NAC) as a pharmacological intervention with glutamatergic, neuroprotective and anti-inflammatory capabilities. RESULTS: This is a double-blind, placebo-controlled RCT with regard to NAC and a single-blind RCT with regard to IPPI using a 2 × 2-factorial design to investigate the individual and combined preventive effects of both interventions. To this aim, a total of 200 CHR subjects will be randomized stratified by site to one of four conditions: (a) IPPI and NAC; (b) IPPI and Placebo; (c) NAC and psychological stress management; (d) Placebo and psychological stress management. Interventions are delivered over 26 weeks with a follow-up period of 12 months. CONCLUSION: This paper reports on the rationale and protocol of an indicated prevention trial to detect the most effective and tolerable interventions with regard to transition to psychosis as well as improvements in social functioning, and to evaluate the synergistic effects of these interventions.


Assuntos
Acetilcisteína/uso terapêutico , Terapia Cognitivo-Comportamental , Transtornos Psicóticos/tratamento farmacológico , Transtornos Psicóticos/prevenção & controle , Transtornos Psicóticos/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Adolescente , Adulto , Antipsicóticos/uso terapêutico , Terapia Combinada/métodos , Método Duplo-Cego , Feminino , Humanos , Masculino , Estudos Multicêntricos como Assunto , Transtornos Psicóticos/psicologia , Método Simples-Cego , Estresse Psicológico/complicações , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/terapia , Adulto Jovem
11.
Brain Stimul ; 12(3): 643-651, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30745260

RESUMO

OBJECTIVE: To assay peripheral inter-ictal cytokine serum levels and possible relations with non-invasive vagus nerve stimulation (nVNS) responsiveness in migraineurs. METHODS: This double-blinded, sham-controlled study enrolled 48 subjects and measured headache severity, frequency [headache days/month, number of total and mild/moderate/severe classified attacks/month], functional state [sleep, mood, body weight, migraine-associated disability] and serum levels of inflammatory markers [inter-ictal] using enzyme-linked immunoassays at baseline and after 2 months of adjunctive nVNS compared to sham stimulation and suitably matched controls. RESULTS: No significant differences were observed at baseline and after 2 months for headache severity, total attacks/month, headache days/month and functional outcome [sleep, mood, disability] between verum and sham nVNS. However, the number of severe attacks/month significantly decreased in the verum nVNS group and circulating pro-inflammatory IL-1ß was elevated significantly in the sham group compared to nVNS. Levels of anti-inflammatory IL-10 were significantly higher at baseline in both groups compared to healthy controls, but not at 2 months follow-up [p < 0.05]. Concentrations of high-mobility group box-1 (HMGB-1), IL-6, tumor-necrosis factor-α (TNF-α), leptin, adiponectin, ghrelin remained unchanged [p > 0.05]. No severe device-/stimulation-related adverse events occurred. CONCLUSION: 2 months of adjunctive cervical nVNS significantly declined the number of severe attacks/month. Pro-inflammatory IL-1ß plasma levels [inter-ictal] were higher in sham-treated migraine patients compared to verum nVNS. However, pro- [IL-6, HMGB-1, TNF-α, leptin] and anti-inflammatory [IL-10, adiponectin, ghrelin] mediators did not differ statistically. Profiling of neuroinflammatory circuits in migraine to predict nVNS responsiveness remains an experimental approach, which may be biased by pre-analytic variables warranting large-scale biobank-based systematic investigations [omics].


Assuntos
Cefaleia Histamínica/terapia , Transtornos de Enxaqueca/terapia , Estimulação do Nervo Vago/métodos , Adulto , Citocinas/sangue , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudo de Prova de Conceito
12.
Neuromodulation ; 22(1): 44-52, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30358008

RESUMO

OBJECTIVES: Complex regional pain syndrome (CRPS) and associated comorbidities have been linked to a pro-inflammatory state driven by different mediators. Targeted dorsal root ganglion stimulation (DRGSTIM ) suppressed pain levels and improved functional capacity in intractable CRPS. However, clinical trials assessing the impact of DRG stimulation on the neuroimmune axis are lacking. METHODS: This study enrolled 24 subjects (12 refractory CRPS patients plus suitably matched healthy controls) and performed immunoassays of inflammatory mediators in saliva and serum along with score-based assessments of pain, mood, and sleep quality at baseline and after three months of selective L4-DRGSTIM . RESULTS: After three-month L4-DRGSTIM CRPS associated pain significantly decreased. In addition, disturbed sleep and mood improved post-DRGSTIM , although statistically not significant. Significantly increased serum values of pro-inflammatory markers were detected pre- and post L4-DRGSTIM for high-mobility group box 1, tumor-necrosis factor α, interleukin (IL) 6, and leptin. IL-1ß was significantly elevated pre-L4 DRGSTIM , but not posttreatment. Elevated anti-inflammatory IL-10 significantly decreased after three months in serum, while saliva oxytocin concentrations increased in CRPS subjects after L4-DRGSTIM (p = 0.65). No severe implantation and stimulation associated adverse events were recorded. CONCLUSIONS: Selective L4-DRGSTIM improved neuropathic pain and functional impairment in CRPS as previously reported. CRPS patients displayed a pro-inflammatory molecular pattern in serum. Serum anti-inflammatory IL-10 significantly declined, while saliva oxytocin nonsignificantly increased after L4-DRGSTIM . An evidence-based relational interpretation of our study is limited due to the uncontrolled study design. However, molecular profiling of biofluids (saliva, serum) represents a novel and experimental field in applied neuromodulation, which warrant further investigations to unveil mechanisms of neuroimmune modulation.


Assuntos
Biomarcadores/análise , Síndromes da Dor Regional Complexa/terapia , Terapia por Estimulação Elétrica/métodos , Gânglios Espinais , Idoso , Feminino , Humanos , Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade , Neuralgia/terapia , Manejo da Dor/métodos , Saliva/química
13.
Behav Brain Sci ; 40: e241, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-29122030

RESUMO

The phylogenetically ancient neuropeptide oxytocin has been linked to a plethora of social behaviors. Here, we argue that the action of oxytocin is not restricted to the downstream level of emotional responses, but substantially alters higher representations of attitudes and values by exerting a distant modulatory influence on cortical areas and their reciprocal interplay with subcortical regions and hormonal systems.


Assuntos
Asco , Ocitocina , Administração Intranasal , Atitude , Emoções , Comportamento Social
14.
Neuroimage ; 141: 52-59, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27402599

RESUMO

INTRODUCTION: Nicotine and methylphenidate are putative cognitive enhancers in healthy and patient populations. Although they stimulate different neurotransmitter systems, they have been shown to enhance performance on overlapping measures of attention. So far, there has been no direct comparison of the effects of these two stimulants on behavioural performance or brain function in healthy humans. Here, we directly compare the two compounds using a well-established oculomotor biomarker in order to explore common and distinct behavioural and neural effects. METHODS: Eighty-two healthy male non-smokers performed a smooth pursuit eye movement task while lying in an fMRI scanner. In a between-subjects, double-blind design, subjects either received placebo (placebo patch and capsule), nicotine (7mg nicotine patch and placebo capsule), or methylphenidate (placebo patch and 40mg methylphenidate capsule). RESULTS: There were no significant drug effects on behavioural measures. At the neural level, methylphenidate elicited higher activation in left frontal eye field compared to nicotine, with an intermediate response under placebo. DISCUSSION: The reduced activation of task-related regions under nicotine could be associated with more efficient neural processing, while increased hemodynamic response under methylphenidate is interpretable as enhanced processing of task-relevant networks. Together, these findings suggest dissociable neural effects of these putative cognitive enhancers.


Assuntos
Lobo Frontal/fisiologia , Metilfenidato/administração & dosagem , Nicotina/administração & dosagem , Desempenho Psicomotor/fisiologia , Acompanhamento Ocular Uniforme/efeitos dos fármacos , Acompanhamento Ocular Uniforme/fisiologia , Campos Visuais/fisiologia , Mapeamento Encefálico , Estimulantes do Sistema Nervoso Central/administração & dosagem , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Lobo Frontal/efeitos dos fármacos , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Percepção de Movimento/efeitos dos fármacos , Percepção de Movimento/fisiologia , Nootrópicos/administração & dosagem , Efeito Placebo , Desempenho Psicomotor/efeitos dos fármacos , Resultado do Tratamento , Campos Visuais/efeitos dos fármacos , Adulto Jovem
16.
Neuropsychologia ; 50(8): 1719-29, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22575084

RESUMO

More than 5 million deaths a year are attributable to tobacco smoking, making it the largest single cause of preventable death worldwide. The primary addictive component in tobacco is nicotine. Its addictive power is exemplified by the fact that by far most attempts to quit smoking fail. It is therefore mandatory to understand the biological mechanisms by which nicotine leads to continued smoking despite its harmful consequences. While current research perspectives on nicotine addiction emphasize the contribution of reward-related mesocorticolimbic dopamine (DA) systems, the role of the amygdala remains less well characterized, although it is crucially engaged in the emotional and motivational modulation of cognition and behavior. Consequently, we here review brain imaging studies reporting altered neural responses of the amygdala in nicotine addiction. A major focus is placed upon resting-state and cue-induction studies documenting that nicotine addiction is associated with aberrant amygdala activity. Importantly, unprovoked abstinence-induced nicotine cravings have been shown to interfere with the amygdala's ability to detect and adequately respond to harm signals. In light of this empirical evidence, we propose that impaired amygdala-guided harm avoidance and executive functions may be instrumental in maintaining nicotine addiction despite serious health consequences.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Nicotina/efeitos adversos , Agonistas Nicotínicos/efeitos adversos , Fumar/efeitos adversos , Síndrome de Abstinência a Substâncias/fisiopatologia , Tabagismo/fisiopatologia , Mapeamento Encefálico , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons
17.
Hum Brain Mapp ; 33(6): 1407-16, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21618661

RESUMO

Cigarette smoking, a major, yet avoidable, cause of disability and premature death, is the most prevalent form of nicotine addiction. An emerging theme in the neurobiology of nicotine addiction is the integrity of the amygdala. Using functional MRI, amygdala responses during a face perception task were compared between 28 chronic smokers [14 females, 14 males; age, 26.3 (2.8) years; age at onset of smoking, 15.8 (2.6) years; years smoked, 9.1 (2.1); cigarettes per day, 17.1 (3.7); Fagerström test for nicotine dependence score, 4.1 (1.9); exhaled carbon-monoxide level, 17.8 (9.5) ppm] and 28 age- and education-matched nonsmokers [14 females, 14 males; age, 26.9 (2.4) years]. Subjects underwent imaging on two separate occasions 1 week apart: smoking satiety versus overnight smoking deprivation, in a randomized counterbalanced order. Our results show no difference in amygdala responses to faces between nonsmokers and satiated smokers. However, overnight deprivation from smoking was associated with a significantly lowered amygdala response to fear, an effect that was probabilistically mapped to the basolateral amygdala. We suggest that aberrant amygdala reactivity in overnight-deprived smokers may reflect a pre-existing vulnerability to smoking and/or increase the risk of smoking relapse after a cessation attempt.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Medo/fisiologia , Fumar/fisiopatologia , Síndrome de Abstinência a Substâncias/fisiopatologia , Percepção Visual/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Personalidade , Abandono do Hábito de Fumar
18.
Neuropsychopharmacology ; 35(4): 1008-15, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20043002

RESUMO

Negative cognitive bias-the tendency to interpret ambiguous situations pessimistically-is a central feature of stress-related disorders such as depression. The underlying neurobiology of this bias, however, remains unclear, not least because of a lack of translational tools. We established a new ambiguous-cue interpretation paradigm and, with respect to the etiology of depression, evaluated if environmental and genetic factors contribute to a negative bias. Rats were trained to press a lever to receive a food reward contingent to one tone and to press another lever in response to a different tone to avoid punishment by electric foot-shock. In the ambiguous-cue test, the lever-press responses to tones with frequencies intermediate to the trained tones were taken as indicators for the rats' expectation of a positive or negative event. A negative response bias because of decreased positive and increased negative responding was found in congenitally helpless rats, a genetic animal model of depression. Moreover, treatment with a combined noradrenergic-glucocorticoid challenge, mimicking stress-related changes in endogenous neuromodulation, biased rats away from positive responding. This response shift was accompanied by neuronal activation in dentate gyrus and amygdala. Thus, environmental and genetic risk factors for depression induce a response bias, which resembles the pessimistic bias of patients suffering from depression. The behavioral paradigm described constitutes a useful tool to study the neuronal basis of decision making under ambiguous conditions and may promote innovative pharmaco- and psychotherapy for depression.


Assuntos
Viés , Sinais (Psicologia) , Depressão/fisiopatologia , Preferências Alimentares/fisiologia , Estresse Psicológico/fisiopatologia , Inibidores da Captação Adrenérgica/farmacologia , Tonsila do Cerebelo/efeitos dos fármacos , Tonsila do Cerebelo/metabolismo , Análise de Variância , Animais , Comportamento Animal , Condicionamento Psicológico/efeitos dos fármacos , Condicionamento Psicológico/fisiologia , Corticosterona/farmacologia , Estudos Cross-Over , Depressão/genética , Discriminação Psicológica/efeitos dos fármacos , Discriminação Psicológica/fisiologia , Modelos Animais de Doenças , Extinção Psicológica/efeitos dos fármacos , Extinção Psicológica/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Comportamento Alimentar/fisiologia , Preferências Alimentares/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Morfolinas/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Reboxetina , Estresse Psicológico/genética
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