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1.
JCPP Adv ; 4(2): e12231, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38827985

RESUMO

Background: A stronger preference for immediate rewards has been reported in individuals with ADHD and other disorders. However, the consistency of the associations between this preference and psychiatric conditions as well as functional outcomes have been questioned. Research on its association with longitudinal outcomes is scarce. Methods: The current study used data on a choice delay task (CDT) from a school-based cohort of Brazilian children with those at higher risk for psychiatric disorders over-sampled (n = 1917). The sample included typically developing children (n = 1379), those with ADHD (n = 213), and other disorders. The frequency of the trials where children chose a larger later reward versus a smaller sooner reward was compared for those with ADHD and typically developing children. Cross-sectionally and longitudinally, the study also evaluated whether children's preference for larger delayed rewards at baseline predicted the presence of psychiatric disorders and functional life outcomes (academic performance, alcohol use, early pregnancy, criminal conviction, BMI). Results: Children with ADHD and their typically developing peers performed similarly on the CDT. Their baseline task performance was not related to psychiatric conditions or life outcomes. Conclusions: The current results raise questions regarding the use of the CDT with diverse populations and whether a preference for larger delayed rewards is predictive of positive long-term outcomes as widely assumed.

2.
Front Psychiatry ; 14: 1191289, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37575579

RESUMO

Introduction: Attention-Deficit/Hyperactivity Disorder (ADHD) is a debilitating condition affecting children and their families worldwide. Behavioral parent training is a recommended form of empirically supported non-pharmacological intervention for young children with mild to moderate ADHD. However, access to such treatment is limited in many countries. Here we identify the treatment needs of Brazilian families with children demonstrating symptoms of ADHD, and the barriers families face in accessing behavioral treatment. Methods: A qualitative needs assessment was undertaken with parents (n = 23), educators (n = 15), and healthcare providers (n = 16). Semi-structured telephone interviews were conducted, and common themes were identified through inductive coding of participants' responses. Results: Participants reported a lack of accessible behavioral treatment, and delays in accessing treatment when available. The majority of parents had not received behavioral parent training, despite it being a recommended form of treatment. Parents, educators and healthcare providers strongly endorsed a need for practical tools to manage the behavior of children with ADHD. Conclusion: Existing services might not meet the needs of children with ADHD and their families in Brazil. Easily accessed behavioral parent training programs are recommended to address the identified treatment gap for Brazilian children with ADHD and their families.

3.
Psychol Med ; 53(12): 5698-5708, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36226568

RESUMO

BACKGROUND: Understanding deviations from typical brain development is a promising approach to comprehend pathophysiology in childhood and adolescence. We investigated if cerebellar volumes different than expected for age and sex could predict psychopathology, executive functions and academic achievement. METHODS: Children and adolescents aged 6-17 years from the Brazilian High-Risk Cohort Study for Mental Conditions had their cerebellar volume estimated using Multiple Automatically Generated Templates from T1-weighted images at baseline (n = 677) and at 3-year follow-up (n = 447). Outcomes were assessed using the Child Behavior Checklist and standardized measures of executive functions and school achievement. Models of typically developing cerebellum were based on a subsample not exposed to risk factors and without mental-health conditions (n = 216). Deviations from this model were constructed for the remaining individuals (n = 461) and standardized variation from age and sex trajectory model was used to predict outcomes in cross-sectional, longitudinal and mediation analyses. RESULTS: Cerebellar volumes higher than expected for age and sex were associated with lower externalizing specific factor and higher executive functions. In a longitudinal analysis, deviations from typical development at baseline predicted inhibitory control at follow-up, and cerebellar deviation changes from baseline to follow-up predicted changes in reading and writing abilities. The association between deviations in cerebellar volume and academic achievement was mediated by inhibitory control. CONCLUSIONS: Deviations in the cerebellar typical development are associated with outcomes in youth that have long-lasting consequences. This study highlights both the potential of typical developing models and the important role of the cerebellum in mental health, cognition and education.


Assuntos
Função Executiva , Transtornos Mentais , Criança , Humanos , Adolescente , Estudos de Coortes , Estudos Transversais , Cerebelo/diagnóstico por imagem
4.
Psychiatry Res Neuroimaging ; 327: 111561, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36334392

RESUMO

Altered reward sensitivity has been proposed to underlie symptoms of attention deficit hyperactivity disorder (ADHD). Functional magnetic resonance imaging (fMRI) studies have reported hypoactivation to reward-predicting cues in the ventral striatum among individuals with ADHD, using experimental designs with and without behavioral response requirements. These studies have typically used monetary incentives as rewards; however, it is unclear if these findings extend to other reward types. The current study examined striatal responses to anticipation and delivery of both affiliative and food reward images using a classical conditioning paradigm. Data from 20 typically developing young adults, and 20 individuals diagnosed with ADHD were included in a region-of-interest analysis for a priori striatal regions. Consistent with findings from studies using monetary rewards, individuals with ADHD showed decreased activation to cues predicting affiliative rewards in the bilateral ventral and dorsal striatum and increased activation to the delivery of affiliative rewards in the ventral striatum. No group differences were found in striatal responses to food reward cues or images. These results suggest hyposensitivity to reward-predicting cues in ADHD extends to affiliative rewards, with important implications for understanding and managing the learning and social functioning of those with ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Estriado Ventral , Adulto Jovem , Humanos , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico por imagem , Recompensa , Estriado Ventral/diagnóstico por imagem , Imageamento por Ressonância Magnética , Motivação
6.
Curr Opin Psychiatry ; 33(3): 255-263, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32049765

RESUMO

PURPOSE OF REVIEW: Mental health and substance use problems are among the most prevalent and challenging problems faced by both high-income and low-income countries worldwide. This review will focus on summarizing scattered evidence of school-based interventions to promote well-being and prevent mental health problems and substance use disorders in children and adolescents. RECENT FINDINGS: We focus on two main areas of research: promotion of healthy school climate and prevention of bullying. Choosing among available interventions might be challenging, both because of the difficulties in assessing their efficacy and tailoring interventions to specific needs, but also because of the scarcity of intervention in low-resource settings. We provide some guidance on principles encompassed by the available evidence that can be used for policymakers and local communities aiming to integrate mental health promotion and prevention into their schools. SUMMARY: Developing, implementing, scaling and sustaining school-based interventions is a necessity of our field if we want to move closer to sustainable development goals.


Assuntos
Promoção da Saúde , Transtornos Mentais/prevenção & controle , Saúde Mental , Serviços de Saúde Escolar , Instituições Acadêmicas , Transtornos Relacionados ao Uso de Substâncias/prevenção & controle , Adolescente , Bullying/prevenção & controle , Criança , Humanos , População Urbana
7.
Neuropharmacology ; 162: 107833, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31689423

RESUMO

Attention deficit hyperactivity disorder (ADHD) has been associated with neural hyposensitivity to reward-predicting cues. Methylphenidate is widely used in the management of the disorder's symptoms, but its effects on reward sensitivity in ADHD are unknown. The current study used fMRI to measure striatal responses to reward-predicting cues in adults with ADHD on and off methylphenidate and a control group, during a classical conditioning task. Responses to cued reward were also explored. Larger differences in the ventral striatum activation to reward cues versus non-reward cues were observed when the ADHD participants were on methylphenidate compared to placebo. In response to cued-reward outcome, an exploratory analysis showed methylphenidate reduced the BOLD time-series correlation between the dorsal striatum and dorsal medial prefrontal cortex. Methylphenidate's therapeutic effects may be mediated by altering reward processing in individuals with ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Inibidores da Captação de Dopamina/farmacologia , Metilfenidato/farmacologia , Neostriado/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Recompensa , Estriado Ventral/efeitos dos fármacos , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico por imagem , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Estudos de Casos e Controles , Condicionamento Clássico , Sinais (Psicologia) , Inibidores da Captação de Dopamina/uso terapêutico , Método Duplo-Cego , Feminino , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Metilfenidato/uso terapêutico , Neostriado/diagnóstico por imagem , Placebos , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiopatologia , Estriado Ventral/diagnóstico por imagem , Estriado Ventral/fisiopatologia , Adulto Jovem
8.
Neuroimage Clin ; 24: 101992, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31505367

RESUMO

Previously, using fMRI, we demonstrated lower connectivity between right anterior superior temporal (ATL) and anterior subgenual cingulate (SCC) regions while patients with major depressive disorder (MDD) experience guilt. This neural signature was detected despite symptomatic remission which suggested a putative role in vulnerability. This randomised controlled double-blind parallel group clinical trial investigated whether patients with MDD are able to voluntarily modulate this neural signature. To this end, we developed a fMRI neurofeedback software (FRIEND), which measures ATL-SCC coupling and displays its levels in real time. Twenty-eight patients with remitted MDD were randomised to two groups, each receiving one session of fMRI neurofeedback whilst retrieving guilt and indignation/anger-related autobiographical memories. They were instructed to feel the emotion whilst trying to increase the level of a thermometer-like display on a screen. Active intervention group: The thermometer levels increased with increasing levels of ATL-SCC correlations in the guilt condition. Control intervention group: The thermometer levels decreased when correlation levels deviated from the previous baseline level in the guilt condition, thus reinforcing stable correlations. Both groups also received feedback during the indignation condition reinforcing stable correlations. We confirmed our predictions that patients in the active intervention group were indeed able to increase levels of ATL-SCC correlations for guilt vs. indignation and their self-esteem after training compared to before training and that this differed significantly from the control intervention group. These data provide proof-of-concept for a novel treatment target for MDD patients and are in keeping with the hypothesis that ATL-SCC connectivity plays a key role in self-worth. https://clinicaltrials.gov/ct2/show/results/NCT01920490.


Assuntos
Transtorno Depressivo Maior/fisiopatologia , Neuroimagem Funcional , Culpa , Giro do Cíngulo/fisiopatologia , Neurorretroalimentação/fisiologia , Autoimagem , Lobo Temporal/fisiopatologia , Adulto , Transtorno Depressivo Maior/diagnóstico por imagem , Método Duplo-Cego , Feminino , Giro do Cíngulo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudo de Prova de Conceito , Lobo Temporal/diagnóstico por imagem
9.
Sci Rep ; 7(1): 16122, 2017 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-29170383

RESUMO

Humans have a strong need to belong to social groups and a natural inclination to benefit ingroup members. Although the psychological mechanisms behind human prosociality have extensively been studied, the specific neural systems bridging group belongingness and altruistic motivation remain to be identified. Here, we used soccer fandom as an ecological framing of group membership to investigate the neural mechanisms underlying ingroup altruistic behaviour in male fans using event-related functional magnetic resonance. We designed an effort measure based on handgrip strength to assess the motivation to earn money (i) for oneself, (ii) for anonymous ingroup fans, or (iii) for a neutral group of anonymous non-fans. While overlapping valuation signals in the medial orbitofrontal cortex (mOFC) were observed for the three conditions, the subgenual cingulate cortex (SCC) exhibited increased functional connectivity with the mOFC as well as stronger hemodynamic responses for ingroup versus outgroup decisions. These findings indicate a key role for the SCC, a region previously implicated in altruistic decisions and group affiliation, in dovetailing altruistic motivations with neural valuation systems in real-life ingroup behaviour.


Assuntos
Altruísmo , Motivação/fisiologia , Recompensa , Futebol , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Empatia/fisiologia , Feminino , Força da Mão/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Comportamento Social , Curetagem Subgengival
10.
Hum Brain Mapp ; 35(7): 3302-13, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25050426

RESUMO

Humans spend a substantial share of their lives mind-wandering. This spontaneous thinking activity usually comprises autobiographical recall, emotional, and self-referential components. While neuroimaging studies have demonstrated that a specific brain "default mode network" (DMN) is consistently engaged by the "resting state" of the mind, the relative contribution of key cognitive components to DMN activity is still poorly understood. Here we used fMRI to investigate whether activity in neural components of the DMN can be differentially explained by active recall of relevant emotional autobiographical memories as compared with the resting state. Our study design combined emotional autobiographical memory, neutral memory and resting state conditions, separated by a serial subtraction control task. Shared patterns of activation in the DMN were observed in both emotional autobiographical and resting conditions, when compared with serial subtraction. Directly contrasting autobiographical and resting conditions demonstrated a striking dissociation within the DMN in that emotional autobiographical retrieval led to stronger activation of the dorsomedial core regions (medial prefrontal cortex, posterior cingulate cortex), whereas the resting state condition engaged a ventral frontal network (ventral striatum, subgenual and ventral anterior cingulate cortices) in addition to the IPL. Our results reveal an as yet unreported dissociation within the DMN. Whereas the dorsomedial component can be explained by emotional autobiographical memory, the ventral frontal one is predominantly associated with the resting state proper, possibly underlying fundamental motivational mechanisms engaged during spontaneous unconstrained ideation.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiologia , Emoções , Memória Episódica , Rememoração Mental/fisiologia , Adulto , Córtex Cerebral/irrigação sanguínea , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Modelos Neurológicos , Vias Neurais/irrigação sanguínea , Vias Neurais/fisiologia , Oxigênio/sangue , Fatores de Tempo , Adulto Jovem
11.
Soc Neurosci ; 9(4): 326-31, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24802255

RESUMO

Attachment to one's kin as an in-group emerges from a fundamental human motivation and is vital for human survival. Despite important recent advances in the field of social neuroscience, the neural mechanisms underlying family-related in-group perception remain obscure. To examine the neural basis of perceiving family-related in-group boundaries in response to written kinship scenarios, we used functional magnetic resonance imaging in 27 healthy adults and obtained self-report ratings of family-related entitativity, which measures to what degree participants perceive their family as a coherent and distinct group in society. We expected that activity in the subgenual cingulate cortex and septo-hypothalamic region would track individual differences in entitativity. Perceiving one's family as a distinct and cohesive group (high entitativity) was associated with increased subgenual cortex response to kinship scenarios. The subgenual cingulate cortex may represent a key link between kin-related emotional attachment and group perception, providing a neurobiological basis for group belongingness.


Assuntos
Família/psicologia , Processos Grupais , Giro do Cíngulo/fisiologia , Pensamento/fisiologia , Adulto , Encéfalo/fisiologia , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Percepção/fisiologia , Autorrelato
12.
PLoS One ; 9(5): e97343, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24847819

RESUMO

In Ridley Scott's film "Blade Runner", empathy-detection devices are employed to measure affiliative emotions. Despite recent neurocomputational advances, it is unknown whether brain signatures of affiliative emotions, such as tenderness/affection, can be decoded and voluntarily modulated. Here, we employed multivariate voxel pattern analysis and real-time fMRI to address this question. We found that participants were able to use visual feedback based on decoded fMRI patterns as a neurofeedback signal to increase brain activation characteristic of tenderness/affection relative to pride, an equally complex control emotion. Such improvement was not observed in a control group performing the same fMRI task without neurofeedback. Furthermore, the neurofeedback-driven enhancement of tenderness/affection-related distributed patterns was associated with local fMRI responses in the septohypothalamic area and frontopolar cortex, regions previously implicated in affiliative emotion. This demonstrates that humans can voluntarily enhance brain signatures of tenderness/affection, unlocking new possibilities for promoting prosocial emotions and countering antisocial behavior.


Assuntos
Empatia/fisiologia , Lobo Frontal/fisiologia , Região Hipotalâmica Lateral/fisiologia , Neurorretroalimentação/métodos , Adulto , Mapeamento Encefálico , Feminino , Lobo Frontal/anatomia & histologia , Humanos , Região Hipotalâmica Lateral/anatomia & histologia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Análise Multivariada , Neurorretroalimentação/instrumentação , Máquina de Vetores de Suporte
13.
PLoS One ; 9(2): e89129, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24586543

RESUMO

Altered reward processing has been proposed to contribute to the symptoms of attention deficit hyperactivity disorder (ADHD). The neurobiological mechanism underlying this alteration remains unclear. We hypothesize that the transfer of dopamine release from reward to reward-predicting cues, as normally observed in animal studies, may be deficient in ADHD. Functional magnetic resonance imaging (fMRI) was used to investigate striatal responses to reward-predicting cues and reward delivery in a classical conditioning paradigm. Data from 14 high-functioning and stimulant-naïve young adults with elevated lifetime symptoms of ADHD (8 males, 6 females) and 15 well-matched controls (8 males, 7 females) were included in the analyses. During reward anticipation, increased blood-oxygen-level-dependent (BOLD) responses in the right ventral and left dorsal striatum were observed in controls, but not in the ADHD group. The opposite pattern was observed in response to reward delivery; the ADHD group demonstrated significantly greater BOLD responses in the ventral striatum bilaterally and the left dorsal striatum relative to controls. In the ADHD group, the number of current hyperactivity/impulsivity symptoms was inversely related to ventral striatal responses during reward anticipation and positively associated with responses to reward. The BOLD response patterns observed in the striatum are consistent with impaired predictive dopamine signaling in ADHD, which may explain altered reward-contingent behaviors and symptoms of ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Corpo Estriado/fisiologia , Recompensa , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
14.
PLoS One ; 8(12): e81658, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24312569

RESUMO

The demonstration that humans can learn to modulate their own brain activity based on feedback of neurophysiological signals opened up exciting opportunities for fundamental and applied neuroscience. Although EEG-based neurofeedback has been long employed both in experimental and clinical investigation, functional MRI (fMRI)-based neurofeedback emerged as a promising method, given its superior spatial resolution and ability to gauge deep cortical and subcortical brain regions. In combination with improved computational approaches, such as pattern recognition analysis (e.g., Support Vector Machines, SVM), fMRI neurofeedback and brain decoding represent key innovations in the field of neuromodulation and functional plasticity. Expansion in this field and its applications critically depend on the existence of freely available, integrated and user-friendly tools for the neuroimaging research community. Here, we introduce FRIEND, a graphic-oriented user-friendly interface package for fMRI neurofeedback and real-time multivoxel pattern decoding. The package integrates routines for image preprocessing in real-time, ROI-based feedback (single-ROI BOLD level and functional connectivity) and brain decoding-based feedback using SVM. FRIEND delivers an intuitive graphic interface with flexible processing pipelines involving optimized procedures embedding widely validated packages, such as FSL and libSVM. In addition, a user-defined visual neurofeedback module allows users to easily design and run fMRI neurofeedback experiments using ROI-based or multivariate classification approaches. FRIEND is open-source and free for non-commercial use. Processing tutorials and extensive documentation are available.


Assuntos
Interfaces Cérebro-Computador , Gráficos por Computador , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Neurorretroalimentação/métodos , Interface Usuário-Computador , Adulto , Mapeamento Encefálico , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Análise Multivariada , Máquina de Vetores de Suporte , Fatores de Tempo
15.
J Neurosci ; 32(36): 12499-505, 2012 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-22956840

RESUMO

Comparative studies have established that a number of structures within the rostromedial basal forebrain are critical for affiliative behaviors and social attachment. Lesion and neuroimaging studies concur with the importance of these regions for attachment and the experience of affiliation in humans as well. Yet it remains obscure whether the neural bases of affiliative experiences can be differentiated from the emotional valence with which they are inextricably associated at the experiential level. Here we show, using functional MRI, that kinship-related social scenarios evocative of affiliative emotion induce septal-preoptic-anterior hypothalamic activity that cannot be explained by positive or negative emotional valence alone. Our findings suggest that a phylogenetically conserved ensemble of basal forebrain structures, especially the septohypothalamic area, may play a key role in enabling human affiliative emotion. Our finding of a neural signature of human affiliative experience bears direct implications for the neurobiological mechanisms underpinning impaired affiliative experiences and behaviors in neuropsychiatric conditions.


Assuntos
Emoções/fisiologia , Hipotálamo Anterior/fisiologia , Septo do Cérebro/fisiologia , Adolescente , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa/métodos , Projetos Piloto , Adulto Jovem
16.
Psychopharmacology (Berl) ; 218(3): 461-70, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21556803

RESUMO

RATIONALE: D -Serine is an endogenous co-agonist of the N-methyl-D: -aspartate (NMDA) receptor and has been suggested to improve cognitive deficits in schizophrenia. OBJECTIVES: The present study investigates the effects of treatment with D -serine in mice on tasks that require recognition learning and working memory, two cognitive domains that are impaired in schizophrenia. METHODS: We studied the effects of various regimens of systemic administration of D -serine (50 mg/kg/day) on BALB/c mice performing object recognition, T-maze alternation, and open-field exploration tasks. For the object recognition task, we also contrasted the effects of D -serine and D -cycloserine and investigated whether D -serine could reverse alterations induced by subchronic injections of the NMDA antagonist MK-801. D -Serine levels after injections were measured by high-performance liquid chromatography. RESULTS: In the object recognition task, pre-training treatment with D -serine or D -cycloserine significantly enhanced recognition memory 24 h after training. A single administration of D -serine 30 min (but not 6 h) after training produced similar enhancement, suggesting an effect on memory consolidation. Daily treatment with D: -serine enhanced both object recognition and T-maze performance over multiple days and improved short-term memory in MK-801-treated mice. D -Serine treatment did not alter open-field exploration. Behavioral effects were accompanied by increased levels of D -serine in the hippocampus of treated animals. CONCLUSIONS: Our results show that treatment with D -serine can improve performance in tasks related to recognition learning and working memory, suggesting that this agent can be useful for the treatment of disorders involving declines in these cognitive domains.


Assuntos
Memória de Curto Prazo/efeitos dos fármacos , Reconhecimento Psicológico/efeitos dos fármacos , Serina/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Ciclosserina/farmacologia , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/metabolismo , Fatores de Tempo
17.
J Neurochem ; 116(2): 281-90, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21070240

RESUMO

D-serine is a co-agonist of NMDA receptor (NMDAR) and plays important roles in synaptic plasticity mechanisms. Serine racemase (SR) is a brain-enriched enzyme that converts L-serine to D-serine. SR interacts with the protein interacting with C-kinase 1 (PICK1), which is known to direct protein kinase C (PKC) to its targets in cells. Here, we investigated whether PKC activity regulates SR activity and D-serine availability in the brain. In vitro, PKC phosphorylated SR and decreased its activity. PKC activation increased SR phosphorylation in serine residues and reduced D-serine levels in astrocyte and neuronal cultures. Conversely, PKC inhibition decreased basal SR phosphorylation and increased cellular D-serine levels. In vivo modulation of PKC activity regulated both SR phosphorylation and D-serine levels in rat frontal cortex. Finally, rats that completed an object recognition task showed decreased SR phosphorylation and increased D-serine/total serine ratios, which was markedly correlated with decreased PKC activity in both cortex and hippocampus. Results indicate that PKC phosphorylates SR in serine residues and regulates D-serine availability in the brain. This interaction may be relevant for the regulation of physiological and pathological mechanisms linked to NMDAR function.


Assuntos
Encéfalo/metabolismo , Proteína Quinase C/fisiologia , Serina/metabolismo , Animais , Animais Recém-Nascidos , Encéfalo/fisiologia , Células Cultivadas , Masculino , Neurônios/enzimologia , Neurônios/metabolismo , Neurônios/fisiologia , Fosforilação/fisiologia , Proteína Quinase C/metabolismo , Racemases e Epimerases/metabolismo , Racemases e Epimerases/fisiologia , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/fisiologia , Reconhecimento Psicológico/fisiologia , Serina/química
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