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1.
Neurobiol Stress ; 21: 100498, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36532372

RESUMO

Background: Childhood adversity has been found to impact stress and brain reward systems but it is unclear whether interactions between these systems might explain resilient vs. non-resilient trajectories following childhood sexual abuse (CSA). To address this gap, we adopted a multimodal approach in which cortisol reactivity to an acute stressor was assessed in conjunction with behavioral and neural measures of reward responsiveness in females with major depressive disorder (MDD) or no psychiatric disorders (i.e., resilient) who experienced CSA compared to females with and without MDD who did not experience abuse. Methods: Latent Class Mixed Modelling (LCMM) identified classes of adults (n = 62; MAge = 26.48, SD = 5.68) characterized by distinct cortisol trajectories in response to a combined social evaluative cold pressor task. Classes were examined for their history of CSA and resilience as well as behavioral and neural measures of reward responsiveness using 128-channel electroencephalography (event-related potentials and source localization analysis). Results: LCMM analysis identified two distinct classes of individuals with increased (Responders) or blunted (Non-Responders) cortisol reactivity to an acute stressor. Unlike Responders, Non-Responders did not modulate reward responses throughout the stress manipulation. No differences emerged between Responders and Non-Responders in terms of CSA or resilience. However, exploratory results showed that blunted cortisol response and non-modulation of reward responses emerged for those who experienced CSA at a younger age. Conclusions: Co-occurring blunted stress and reward reactivity emerged irrespective of adults' experience of CSA or resilience. However, preliminary findings showed that CSA ending during peripubertal development was associated with blunted cortisol and reward responsiveness. Future research needs to replicate findings in larger samples and could investigate if increasing reward responsiveness during critical times of neurodevelopment could normalize stress reactivity to future stressors and thus promote resilience.

2.
Neuroimage Clin ; 36: 103164, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36044792

RESUMO

Early life stress (ELS) and major depressive disorder (MDD) share neural network abnormalities. However, it is unclear how ELS and MDD may separately and/or jointly relate to brain networks, and whether neural differences exist between depressed individuals with vs without ELS. Moreover, prior work evaluated static versus dynamic network properties, a critical gap considering brain networks show changes in coordinated activity over time. Seventy-one unmedicated females with and without childhood sexual abuse (CSA) histories and/or MDD completed a resting state scan and a stress task in which cortisol and affective ratings were collected. Recurring functional network co-activation patterns (CAPs) were examined and time in CAP (number of times each CAP is expressed) and transition frequencies (transitioning between different CAPs) were computed. The effects of MDD and CSA on CAP metrics were examined and CAP metrics were correlated with depression and stress-related variables. Results showed that MDD, but not CSA, related to CAP metrics. Specifically, individuals with MDD (N = 35) relative to HCs (N = 36), spent more time in a posterior default mode (DMN)-frontoparietal network (FPN) CAP and transitioned more frequently between posterior DMN-FPN and prototypical DMN CAPs. Across groups, more time spent in a posterior DMN-FPN CAP and greater DMN-FPN and prototypical DMN CAP transition frequencies were linked to higher rumination. Imbalances between the DMN and the FPN appear central to MDD and might contribute to MDD-related cognitive dysfunction, including rumination. Unexpectedly, CSA did not modulate such dysfunctions, a finding that needs to be replicated by future studies with larger sample sizes.


Assuntos
Transtorno Depressivo Maior , Delitos Sexuais , Feminino , Criança , Humanos , Vias Neurais , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos
3.
Commun Biol ; 5(1): 236, 2022 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-35301411

RESUMO

Brain derived neurotrophic factor (BDNF) promotes the growth, differentiation, maintenance and survival of neurons. These attributes make BDNF a potentially powerful therapeutic agent. However, its charge, instability in blood, and poor blood brain barrier (BBB) penetrability have impeded its development. Here, we show that engineered clathrin triskelia (CT) conjugated to BDNF (BDNF-CT) and delivered intranasally increased hippocampal BDNF concentrations 400-fold above that achieved previously with intranasal BDNF alone. We also show that BDNF-CT targeted Tropomyosin receptor kinase B (TrkB) and increased TrkB expression and downstream signaling in iTat mouse brains. Mice were induced to conditionally express neurotoxic HIV Transactivator-of-Transcription (Tat) protein that decreases BDNF. Down-regulation of BDNF is correlated with increased severity of HIV/neuroAIDS. BDNF-CT enhanced neurorestorative effects in the hippocampus including newborn cell proliferation and survival, granule cell neurogenesis, synaptogenesis and increased dendritic integrity. BDNF-CT exerted cognitive-enhancing effects by reducing Tat-induced learning and memory deficits. These results show that CT bionanoparticles efficiently deliver BDNF to the brain, making them potentially powerful tools in regenerative medicine.


Assuntos
Infecções por HIV , Nanopartículas , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Clatrina/metabolismo , Cognição , Medicamentos de Ervas Chinesas , Infecções por HIV/metabolismo , Hipocampo/metabolismo , Camundongos , Neurogênese/fisiologia
4.
J Cogn Neurosci ; 34(5): 864-876, 2022 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-35195725

RESUMO

Errors in performance trigger cognitive and neural changes that are implemented to adaptively adjust to fluctuating demands. Error-related alpha suppression (ERAS)-which refers to decreased power in the alpha frequency band after an incorrect response-is thought to reflect cognitive arousal after errors. Much of this work has been correlational, however, and there are no direct investigations into its pharmacological sensitivity. In Study 1 (n = 61), we evaluated the presence and scalp distribution of ERAS in a novel flanker task specifically developed for cross-species assessments. Using this same task in Study 2 (n = 26), which had a placebo-controlled within-subject design, we evaluated the sensitivity of ERAS to placebo (0 mg), low (100 mg), and high (200 mg) doses of modafinil, a wakefulness promoting agent. Consistent with previous work, ERAS was maximal at parieto-occipital recording sites in both studies. In Study 2, modafinil did not have strong effects on ERAS (a significant Accuracy × Dose interaction emerged, but drug-placebo differences did not reach statistical significance after correction for multiple comparisons and was absent after controlling for accuracy rate). ERAS was correlated with accuracy rates in both studies. Thus, modafinil did not impact ERAS as hypothesized, and findings indicate ERAS may reflect an orienting response to infrequent events.


Assuntos
Compostos Benzidrílicos , Couro Cabeludo , Nível de Alerta , Compostos Benzidrílicos/farmacologia , Compostos Benzidrílicos/uso terapêutico , Método Duplo-Cego , Humanos , Modafinila/farmacologia , Modafinila/uso terapêutico , Vigília
5.
Neuropsychopharmacology ; 46(7): 1252-1262, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33746206

RESUMO

Progress towards understanding neural mechanisms in humans relevant to psychiatric conditions has been hindered by a lack of translationally-relevant cognitive tasks for laboratory animals. Accordingly, there is a critical need to develop parallel neurophysiological assessments of domains of cognition, such as cognitive control, in humans and laboratory animals. To address this, we developed a touchscreen-based cognitive (Eriksen Flanker) task in rats and used its key characteristics to construct a novel human version, with similar testing parameters and endpoints across species. We obtained continuous electroencephalogram (EEG) recordings, including local field potentials in rats, and compared electrophysiological signatures locked to stimulus onset and responses across species. We also assessed whether behavioral or physiological task effects were modulated by modafinil, which enhances aspects of cognitive function in humans. In both species, the task elicited expected flanker interference effects (reduced accuracy) during high-conflict trials. Across homologous neuroanatomical loci, stimulus-locked increases in theta power during high-conflict trials as well as error-related negative potentials were observed. These endpoints were not affected by modafinil in either species. Despite some species-specific patterns, our findings demonstrate the feasibility of a rat Flanker task as well as cross-species behavioral and neurophysiological similarities, which may enable novel insights into the neural correlates of healthy and aberrant behavior and provide mechanistic insights relevant to treatment.


Assuntos
Cognição , Eletroencefalografia , Animais , Humanos , Ratos , Tempo de Reação
6.
Artigo em Inglês | MEDLINE | ID: mdl-31784354

RESUMO

BACKGROUND: Theoretical models have emphasized systems-level abnormalities in major depressive disorder (MDD). For unbiased yet rigorous evaluations of pathophysiological mechanisms underlying MDD, it is critically important to develop data-driven approaches that harness whole-brain data to classify MDD and evaluate possible normalizing effects of targeted interventions. Here, using an experimental therapeutics approach coupled with machine learning, we investigated the effect of a pharmacological challenge aiming to enhance dopaminergic signaling on whole-brain response to reward-related stimuli in MDD. METHODS: Using a double-blind, placebo-controlled design, we analyzed functional magnetic resonance imaging data from 31 unmedicated MDD participants receiving a single dose of 50 mg amisulpride (MDDAmisulpride), 26 MDD participants receiving placebo (MDDPlacebo), and 28 healthy control subjects receiving placebo (HCPlacebo) recruited through two independent studies. An importance-guided machine learning technique for model selection was used on whole-brain functional magnetic resonance imaging data probing reward anticipation and consumption to identify features linked to MDD (MDDPlacebo vs. HCPlacebo) and dopaminergic enhancement (MDDAmisulpride vs. MDDPlacebo). RESULTS: Highly predictive classification models emerged that distinguished MDDPlacebo from HCPlacebo (area under the curve = 0.87) and MDDPlacebo from MDDAmisulpride (area under the curve = 0.89). Although reward-related striatal activation and connectivity were among the most predictive features, the best truncated models based on whole-brain features were significantly better relative to models trained using striatal features only. CONCLUSIONS: Results indicate that in MDD, enhanced dopaminergic signaling restores abnormal activation and connectivity in a widespread network of regions. These findings provide new insights into the pathophysiology of MDD and pharmacological mechanism of antidepressants at the system level in addressing reward processing deficits among depressed individuals.


Assuntos
Amissulprida , Antidepressivos de Segunda Geração , Transtorno Depressivo Maior , Dopamina , Aprendizado de Máquina , Recompensa , Adulto , Amissulprida/uso terapêutico , Antidepressivos de Segunda Geração/uso terapêutico , Depressão , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/fisiopatologia , Dopamina/metabolismo , Método Duplo-Cego , Feminino , Humanos , Masculino , Adulto Jovem
7.
Drug Alcohol Depend ; 206: 107728, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31740207

RESUMO

BACKGROUND: Striatal neuroadaptations are regarded to play an important role in the progression from voluntary to compulsive use of addictive substances and provide a promising target for the identification of neuroimaging biomarkers. Recent advances in surface-based computational analysis enable morphological assessment linking variations in global and local striatal shape to duration and magnitude of substance use with a degree of sensitivity that exceeds standard volumetric analysis. METHODS: This study used a new segmentation methodology coupled with local surface-based indices of surface area and displacement to provide a comprehensive structural characterization of the striatum in 34 patients entering treatment for substance use disorder (SUD) and 49 controls, and to examine the influence of recent substance use on abnormal age-related striatal deformation in SUD patients. RESULTS: Patients showed a small reduction in striatal volume and no difference in surface area or shape in comparison to controls. Between-group differences in shape were likely neutralized by the bidirectional influence of recent substance use on striatal shape in SUD patients. Specifically, there was an interaction between age and substance such that among older patients more drug use was associated with greater inward striatal contraction but more alcohol use was associated with greater outward expansion. CONCLUSIONS: This study builds on previous work and advances our understanding of the nature of striatal neuroadaptations as a potential biomarker of disease progression in addiction.


Assuntos
Fatores Etários , Corpo Estriado/patologia , Transtornos Relacionados ao Uso de Substâncias/patologia , Adulto , Biomarcadores/análise , Biologia Computacional , Progressão da Doença , Feminino , Humanos , Masculino , Tamanho do Órgão , Transtornos Relacionados ao Uso de Substâncias/terapia
8.
JAMA Psychiatry ; 76(8): 854-861, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31042280

RESUMO

Importance: Major depressive disorder (MDD) might involve dopamine (DA) reductions. The DA transporter (DAT) regulates DA clearance and neurotransmission and is sensitive to DA levels, with preclinical studies (including those involving inescapable stressors) showing that DAT density decreases when DA signaling is reduced. Despite preclinical data, evidence of reduced DAT in MDD is inconclusive. Objective: Using a highly selective DAT positron emission tomography (PET) tracer ([11C] altropane), DAT availability was probed in individuals with MDD who were not taking medication. Levels of DAT expression were also evaluated in postmortem tissues from donors with MDD who died by suicide. Design, Setting, and Participants: This cross-sectional PET study was conducted at McLean Hospital (Belmont, Massachusetts) and Massachusetts General Hospital (Boston) and enrolled consecutive individuals with MDD who were not taking medication and demographically matched healthy controls between January 2012 and March 2014. Brain tissues were obtained from the Douglas-Bell Canada Brain Bank. For the PET component, 25 individuals with current MDD who were not taking medication and 23 healthy controls recruited from McLean Hospital were included (all provided usable data). For the postmortem component, 15 individuals with depression and 14 healthy controls were considered. Intervention: PET scan. Main Outcomes and Measures: Striatal and midbrain DAT binding potential was assessed. For the postmortem component, tyrosine hydroxylase and DAT levels were evaluated using Western blots. Results: Compared with 23 healthy controls (13 women [56.5%]; mean [SD] age, 26.49 [7.26] years), 25 individuals with MDD (19 women [76.0%]; mean [SD] age, 26.52 [5.92] years) showed significantly lower in vivo DAT availability in the bilateral putamen and ventral tegmental area (Cohen d range, -0.62 to -0.71), and both reductions were exacerbated with increasing numbers of depressive episodes. Unlike healthy controls, the MDD group failed to show an age-associated reduction in striatal DAT availability, with young individuals with MDD being indistinguishable from older healthy controls. Moreover, DAT availability in the ventral tegmental area was lowest in individuals with MDD who reported feeling trapped in stressful circumstances. Lower DAT levels (and tyrosine hydroxylase) in the putamen of MDD compared with healthy controls were replicated in postmortem analyses (Cohen d range, -0.92 to -1.15). Conclusions and Relevance: Major depressive disorder, particularly with recurring episodes, is characterized by decreased striatal DAT expression, which might reflect a compensatory downregulation due to low DA signaling within mesolimbic pathways.


Assuntos
Autopsia , Transtorno Depressivo Maior/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Neostriado/metabolismo , Tomografia por Emissão de Pósitrons , Adulto , Radioisótopos de Carbono/farmacocinética , Cocaína/análogos & derivados , Cocaína/farmacocinética , Estudos Transversais , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/fisiopatologia , Dopaminérgicos/farmacocinética , Feminino , Humanos , Masculino , Neostriado/diagnóstico por imagem , Recidiva , Bancos de Tecidos , Adulto Jovem
9.
Neuroimage ; 169: 443-452, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29288867

RESUMO

The hippocampus is a highly stress susceptible structure and hippocampal abnormalities have been reported in a host of psychiatric disorders including major depression and post-traumatic stress disorder (PTSD). The hippocampus appears to be particularly susceptible to early life stress with a graded reduction in volume based on number of types (multiplicity) or severity of maltreatment. We assessed whether the most important predictors of adult hippocampal volume were multiplicity, severity or duration of exposure or timing of maltreatment during developmental sensitive periods. 3T MRIs were collected on 336 unmedicated, right-handed subjects (132M/204F, 18-25 years). Exposure to broad categories of abuse and neglect during each year of childhood were assessed using the Maltreatment and Abuse Chronology of Exposure scale and evaluated using artificial intelligence and predictive analytics. Male hippocampal volume was predicted by neglect, but not abuse, up through 7 years of age. Female hippocampal volume was predicted by abuse, but not neglect, at 10, 11, 15 and 16 years. Exposure at peak age had greater predictive importance than multiplicity, severity or duration. There were also marked gender differences in subfields and portions (head, body or tail) affected by exposure. History and symptoms of major depression, PTSD or anxiety disorders were not predictive of hippocampal volume once maltreatment was accounted for. Neglect appears to foster inadequate hippocampal development in males while abuse appears to produce a stress-related deficit in females. Studies assessing hippocampal volume in psychiatric disorders need to control for the gender-specific effects of abuse and neglect.


Assuntos
Sobreviventes Adultos de Maus-Tratos Infantis , Hipocampo , Estresse Psicológico , Adolescente , Adulto , Região CA1 Hipocampal/diagnóstico por imagem , Região CA1 Hipocampal/crescimento & desenvolvimento , Região CA1 Hipocampal/patologia , Região CA3 Hipocampal/diagnóstico por imagem , Região CA3 Hipocampal/crescimento & desenvolvimento , Região CA3 Hipocampal/patologia , Feminino , Hipocampo/diagnóstico por imagem , Hipocampo/crescimento & desenvolvimento , Hipocampo/patologia , Humanos , Masculino , Fatores Sexuais , Estresse Psicológico/complicações , Estresse Psicológico/diagnóstico por imagem , Estresse Psicológico/patologia , Adulto Jovem
10.
Artigo em Inglês | MEDLINE | ID: mdl-29057370

RESUMO

BACKGROUND: The prevalence of major depression in those with HIV/AIDS is substantially higher than in the general population. Mechanisms underlying this comorbidity are poorly understood. HIV-transactivator of transcription (Tat) protein, produced and excreted by HIV, could be involved. We determined whether conditional Tat protein expression in mice is sufficient to induce depression-like behaviors and oxidative stress. Further, as oxidative stress is associated with depression, we determined whether decreasing or increasing oxidative stress by administering methylsulfonylmethane (MSM) or diethylmaleate (DEM), respectively, altered depression-like behavior. METHODS: GT-tg bigenic mice received intraperitoneal saline or doxycycline (Dox, 25-100 mg/kg/day) to induce Tat expression. G-tg mice, which do not express Tat protein, also received Dox. Depression-like behavior was assessed with the tail suspension test (TST) and the two-bottle saccharin/water consumption task. Reactive oxygen/nitrogen species (ROS/RNS) were assessed ex vivo. Medial frontal cortex (MFC) oxidative stress and temperature were measured in vivo with 9.4-Tesla proton magnetic resonance spectroscopy (MRS). RESULTS: Tat expression increased TST immobility time in an exposure-dependent manner and reduced saccharin consumption. MSM decreased immobility time while DEM increased it in saline-treated GT-tg mice. Tat and MSM behavioral effects persisted for 28 days. Tat and DEM increased while MSM decreased ROS/RNS levels. Tat expression increased MFC glutathione levels and temperature. CONCLUSIONS: Tat expression induced rapid and enduring depression-like behaviors and oxidative stress. Increasing/decreasing oxidative stress increased/decreased, respectively, depression-like behavior. Thus, Tat produced by HIV may contribute to the high depression prevalence among those with HIV. Further, mitigation of oxidative stress could reduce depression severity.

11.
Biol Psychiatry ; 82(8): 570-577, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28506437

RESUMO

BACKGROUND: Stress is widely known to alter behavioral responses to rewards and punishments. It is believed that stress may precipitate these changes through modulation of corticostriatal circuitry involved in reinforcement learning and motivation, although the intervening mechanisms remain unclear. One candidate is inflammation, which can rapidly increase following stress and can disrupt dopamine-dependent reward pathways. METHODS: Here, in a sample of 88 healthy female participants, we first assessed the effect of an acute laboratory stress paradigm on levels of plasma interleukin-6 (IL-6), a cytokine known to be both responsive to stress and elevated in depression. In a second laboratory session, we examined the effects of a second laboratory stress paradigm on reward prediction error (RPE) signaling in the ventral striatum. RESULTS: We show that individual differences in stress-induced increases in IL-6 (session 1) were associated with decreased ventral striatal RPE signaling during reinforcement learning (session 2), though there was no main effect of stress on RPE. Furthermore, changes in IL-6 following stress predicted intraindividual variability in perceived stress during a 4-month follow-up period. CONCLUSIONS: Taken together, these data identify a novel link between IL-6 and striatal RPEs during reinforcement learning in the context of acute psychological stress, as well as future appraisal of stressful life events.


Assuntos
Corpo Estriado/patologia , Interleucina-6/sangue , Estresse Psicológico/sangue , Estresse Psicológico/patologia , Análise de Variância , Corpo Estriado/diagnóstico por imagem , Feminino , Seguimentos , Voluntários Saudáveis , Humanos , Hidrocortisona/metabolismo , Processamento de Imagem Assistida por Computador , Interleucina-6/metabolismo , Imageamento por Ressonância Magnética , Modelos Estatísticos , Oxigênio/sangue , Análise de Regressão , Reforço Psicológico , Saliva/metabolismo , Estresse Psicológico/diagnóstico por imagem , Estresse Psicológico/fisiopatologia , Fatores de Tempo , Escala Visual Analógica
12.
J Cereb Blood Flow Metab ; 37(2): 564-576, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26873885

RESUMO

It is widely known that blood oxygenation level dependent (BOLD) contrast in functional magnetic resonance imaging (fMRI) is an indirect measure for neuronal activations through neurovascular coupling. The BOLD signal is also influenced by many non-neuronal physiological fluctuations. In previous resting state (RS) fMRI studies, we have identified a moving systemic low frequency oscillation (sLFO) in BOLD signal and were able to track its passage through the brain. We hypothesized that this seemingly intrinsic signal moves with the blood, and therefore, its dynamic patterns represent cerebral blood flow. In this study, we tested this hypothesis by performing Dynamic Susceptibility Contrast (DSC) MRI scans (i.e. bolus tracking) following the RS scans on eight healthy subjects. The dynamic patterns of sLFO derived from RS data were compared with the bolus flow visually and quantitatively. We found that the flow of sLFO derived from RS fMRI does to a large extent represent the blood flow measured with DSC. The small differences, we hypothesize, are largely due to the difference between the methods in their sensitivity to different vessel types. We conclude that the flow of sLFO in RS visualized by our time delay method represents the blood flow in the capillaries and veins in the brain.


Assuntos
Encéfalo/irrigação sanguínea , Circulação Cerebrovascular , Imageamento por Ressonância Magnética/métodos , Adulto , Mapeamento Encefálico/métodos , Humanos , Pessoa de Meia-Idade , Oxigênio/sangue , Perfusão/métodos
13.
Am J Psychiatry ; 174(4): 378-386, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27771973

RESUMO

OBJECTIVE: Major depressive disorder is characterized by reduced reward-related striatal activation and dysfunctional reward learning, putatively reflecting decreased dopaminergic signaling. The goal of this study was to test whether a pharmacological challenge designed to facilitate dopaminergic transmission can enhance striatal responses to reward and improve reward learning in depressed individuals. METHOD: In a double-blind placebo-controlled design, 46 unmedicated depressed participants and 43 healthy control participants were randomly assigned to receive either placebo or a single low dose (50 mg) of the D2/D3 receptor antagonist amisulpride, which is believed to increase dopamine signaling through presynaptic autoreceptor blockade. To investigate the effects of increased dopaminergic transmission on reward-related striatal function and behavior, a monetary incentive delay task (in conjunction with functional MRI) and a probabilistic reward learning task were administered at absorption peaks of amisulpride. RESULTS: Depressed participants selected previously rewarded stimuli less frequently than did control participants, indicating reduced reward learning, but this effect was not modulated by amisulpride. Relative to depressed participants receiving placebo (and control participants receiving amisulpride), depressed participants receiving amisulpride exhibited increased striatal activation and potentiated corticostriatal functional connectivity between the nucleus accumbens and the midcingulate cortex in response to monetary rewards. Stronger corticostriatal connectivity in response to rewards predicted better reward learning among depressed individuals receiving amisulpride as well as among control participants receiving placebo. CONCLUSIONS: Acute enhancement of dopaminergic transmission potentiated reward-related striatal activation and corticostriatal functional connectivity in depressed individuals but had no behavioral effects. Taken together, the results suggest that targeted pharmacological treatments may normalize neural correlates of reward processing in depression; despite such acute effects on neural function, behavioral modification may require more chronic exposure. This is consistent with previous reports that antidepressant effects of amisulpride in depression emerged after sustained administration.


Assuntos
Corpo Estriado/efeitos dos fármacos , Corpo Estriado/fisiopatologia , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/fisiopatologia , Antagonistas de Dopamina/uso terapêutico , Dopamina/fisiologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/fisiologia , Imageamento por Ressonância Magnética , Recompensa , Sulpirida/análogos & derivados , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia , Adulto , Amissulprida , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Sinais (Psicologia) , Transtorno Depressivo Maior/prevenção & controle , Método Duplo-Cego , Feminino , Humanos , Masculino , Motivação/efeitos dos fármacos , Motivação/fisiologia , Sulpirida/uso terapêutico
14.
BMC Psychiatry ; 16(1): 399, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27842519

RESUMO

BACKGROUND: Deep brain stimulation (DBS) has been shown to be effective for parkinsonian symptoms poorly responsive to medications. DBS is typically well-tolerated, as are the maintenance battery changes. Here we describe an adverse event during a battery replacement procedure that caused rapid onset of severe depression. CASE PRESENTATION: The patient is a 58-year-old woman who was in a serious motor vehicle accident and sustained a concussion with loss of consciousness. Within weeks of the accident she began developing parkinsonian symptoms that progressively worsened over the subsequent 10 years. Responding poorly to medications, she received DBS, which controlled her movement symptoms. Five years after initiating DBS, during a routine battery change, an apparent electrical event occurred that triggered the rapid onset of severe depression. Anti-seizure and antidepressant medications were ineffective, and the patient was offered a course of electroconvulsive therapy (ECT), which resulted in complete reversal of her depressive episode. CONCLUSION: Parkinson's syndrome can be seen after a single closed head injury event. Post-traumatic parkinsonism is responsive to DBS; however, DBS has been associated with an infrequent occurrence of dramatic disruption in mood. ECT is a therapeutic option for patients who develop intractable depressive illness associated with DBS.


Assuntos
Estimulação Encefálica Profunda/efeitos adversos , Depressão , Eletroconvulsoterapia/métodos , Doença de Parkinson , Traumatismos Craniocerebrais/complicações , Estimulação Encefálica Profunda/métodos , Depressão/diagnóstico , Depressão/etiologia , Depressão/terapia , Feminino , Humanos , Pessoa de Meia-Idade , Doença de Parkinson/etiologia , Doença de Parkinson/psicologia , Doença de Parkinson/terapia , Escalas de Graduação Psiquiátrica , Resultado do Tratamento
15.
Front Neurosci ; 10: 313, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27445680

RESUMO

Blood-oxygen-level dependent (BOLD) signals are widely used in functional magnetic resonance imaging (fMRI) as a proxy measure of brain activation. However, because these signals are blood-related, they are also influenced by other physiological processes. This is especially true in resting state fMRI, during which no experimental stimulation occurs. Previous studies have found that the amplitude of resting state BOLD is closely related to regional vascular density. In this study, we investigated how some of the temporal fluctuations of the BOLD signal also possibly relate to regional vascular density. We began by identifying the blood-bound systemic low-frequency oscillation (sLFO). We then assessed the distribution of all voxels based on their correlations with this sLFO. We found that sLFO signals are widely present in resting state BOLD signals and that the proportion of these sLFOs in each voxel correlates with different tissue types, which vary significantly in underlying vascular density. These results deepen our understanding of the BOLD signal and suggest new imaging biomarkers based on fMRI data, such as amplitude of low-frequency fluctuation (ALFF) and sLFO, a combination of both, for assessing vascular density.

16.
J Neuropsychiatry Clin Neurosci ; 28(4): 325-327, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26792100

RESUMO

This study examined default mode network connectivity within the first 30 days of abstinence in emerging adults entering treatment for opioid dependence. There were significant associations between abstinence duration and coupling strength with brain regions within and outside of the network.

17.
Neuroimage Clin ; 9: 348-54, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26594618

RESUMO

Impaired brain energy metabolism is among the leading hypotheses in the pathogenesis of affective disorders and linking energy phosphates with states of tissue-function activity is a novel and non-invasive approach to differentiate healthy from unhealthy states. Resting state functional MRI (fMRI) has been established as an important tool for mapping cerebral regional activity and phosphorous chemical shift imaging ((31)P CSI) has been applied to measure levels of energy phosphates and phospholipids non-invasively in order to gain insight into the possible etiology of affective disorders. This is an initial attempt to identify the existence of a correlation between regional energy phosphates and connectivity at nodes of the posterior default mode network (DMN). Resting state fMRI in conjunction with (31)P 2D CSI was applied to 11 healthy controls and 11 depressed patients at 3 T. We found that differences between the two groups exist in correlation of lateral posterior parietal cortex functional connectivity and regional Pi/PCr. Results of this study indicate that resting-state-fMRI-guided (31)P CSI can provide new insight into depression via regional energy phosphates and functional connectivity.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiopatologia , Transtorno Depressivo/metabolismo , Transtorno Depressivo/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Idoso , Encéfalo/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosfatos/metabolismo
18.
Front Psychiatry ; 6: 42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25870565

RESUMO

BACKGROUND: The adverse childhood experience (ACE) study found that risk for depression increased as a function of number of types of childhood maltreatment, and interpret this as a result of cumulative stress. An alternative hypothesis is that risk depends on type and timing of maltreatment. This will also present as a linear increase, since exposure to more types of abuse increases likelihood of experiencing a critical type of abuse at a critical age. METHODS: 560 (223M/337F) young adults (18-25 years) were recruited from the community without regard to diagnosis and balanced to have equal exposure to 0-4 plus types of maltreatment. The Maltreatment and Abuse Chronology of Exposure Scale assessed severity of exposure to 10 types of maltreatment across each year of childhood. Major depressive disorder (MDD) and current symptoms were evaluated by SCID, interview, and self-report. Predictive analytics assessed importance of exposure at each age and evaluated whether exposure at one or two ages was a more important predictor than number, severity, or duration of maltreatment across childhood. RESULTS: The most important predictors of lifetime history of MDD were non-verbal emotional abuse in males and peer emotional abuse (EA) in females at 14 years of age, and these were more important predictors across models than number of types of maltreatment (males: t 9 = 16.39, p < 10(-7); females t 9 = 5.78, p < 10(-4)). Suicidal ideation was predicted, in part, by NVEA and peer EA at age 14, but most importantly by parental verbal abuse at age 5 in males and sexual abuse at age 18 in females. CONCLUSION: This study provides evidence for sensitive exposure periods when maltreatment maximally impacts risk for depression, and provides an alternative interpretation of the ACE study results. These findings fit with emerging neuroimaging evidence for regional sensitivity periods. The presence of sensitive exposure periods has important implications for prevention, preemption, and treatment of MDD.

19.
Biol Psychiatry ; 76(3): 186-93, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24331545

RESUMO

BACKGROUND: We previously reported rapid mood elevation following an experimental magnetic resonance imaging procedure in depressed patients with bipolar disorder (BPD). This prompted the design, construction, and testing of a portable electromagnetic device that reproduces only the rapidly oscillating (1 kHz, <1 V/m) electromagnetic field of the experimental procedure, called low field magnetic stimulation (LFMS). METHODS: We used a randomized, double blind, sham controlled treatment protocol to study the effects of LFMS in a large group of stably medicated, depressed patients with either BPD (n = 41) or major depressive disorder (n = 22). Subjects received a single, 20-minute treatment. Change in mood was assessed immediately afterward using a visual analog scale (VAS), the 17-item Hamilton Depression Rating Scale (HDRS-17), and the Positive and Negative Affect Schedule scales. RESULTS: Substantial improvement (>10% of baseline) in mood was observed following LFMS treatment relative to sham treatment for both diagnostic subgroups for our primary outcomes, the VAS and the HDRS-17. These differences were not statistically significant in primary analyses stratifying by diagnosis but were significant in secondary analyses combining data across the two diagnostic groups (p = .01 VAS, p = .02 HDRS-17). Rapid improvement in mood was also observed using the Positive and Negative Affect Schedule scales as secondary measures (positive affect scale p = .02 BPD, p = .002 combined group). A finite element method calculation indicates a broad penetration of the LFMS electric field throughout the cerebral cortex. CONCLUSIONS: Low field magnetic stimulation may produce rapid changes in mood using a previously unexplored range of electromagnetic fields.


Assuntos
Afeto/fisiologia , Transtorno Bipolar/terapia , Encéfalo/fisiopatologia , Transtorno Depressivo Maior/terapia , Magnetoterapia/instrumentação , Adulto , Método Duplo-Cego , Campos Eletromagnéticos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
20.
PLoS One ; 8(1): e54536, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23382910

RESUMO

BACKGROUND: Research exploring Bipolar Disorder (BD) phenotypes and mitochondrial dysfunction, particularly in younger subjects, has been insufficient to date. Previous studies have found abnormal cerebral pH levels in adults with BD, which may be directly linked to abnormal mitochondrial activity. To date no such studies have been reported in children with BD. METHODS: Phosphorus Magnetic Resonance Spectroscopy ((31)P MRS) was used to determine pH, phopshocreatine (PCr) and inorganic phosphate (Pi) levels in 8 subjects with BD and 8 healthy comparison subjects (HCS) ages 11 to 20 years old. RESULTS: There was no significant difference in pH between the patients and HCS. However, frontal pH values for patients with BD increased with age, contrary to studies of HCS and the pH values in the frontal lobe correlated negatively with the YMRS values. Global Pi was significantly lower in subjects with BD compared with HCS. There were no significant differences in PCr between the groups. Global PCr-to-Pi ratio (PCr/Pi) was significantly higher in subjects with BD compared with HCS. CONCLUSIONS: The change in Pi levels for the patients with BD coupled with the no difference in PCr levels, suggest an altered mitochondrial phosphorylation. However, our findings require further investigation of the underlying mechanisms with the notion that a mitochondrial dysfunction may manifest itself differently in children than that in adults. LIMITATIONS: Further investigations with larger patient populations are necessary to draw further conclusions.


Assuntos
Transtorno Bipolar/metabolismo , Metabolismo Energético , Adolescente , Transtorno Bipolar/diagnóstico , Criança , Feminino , Humanos , Concentração de Íons de Hidrogênio , Imageamento por Ressonância Magnética , Masculino , Ressonância Magnética Nuclear Biomolecular , Fosfatos/metabolismo , Fosfocreatina/metabolismo , Adulto Jovem
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