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1.
Mol Psychiatry ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39261671

RESUMO

Psychedelics have recently attracted significant attention for their potential to mitigate symptoms associated with various psychiatric disorders. However, the precise neurobiological mechanisms responsible for these effects remain incompletely understood. A valuable approach to gaining insights into the specific mechanisms of action involves comparing psychedelics with substances that have partially overlapping neurophysiological effects, i.e., modulating the same neurotransmitter systems. Imaging data were obtained from the clinical trial NCT03019822, which explored the acute effects of lysergic acid diethylamide (LSD), d-amphetamine, and 3,4-methylenedioxymethamphetamine (MDMA) in 28 healthy volunteers. The clinical trial employed a double-blind, placebo-controlled, crossover design. Herein, various resting-state connectivity measures were examined, including within-network connectivity (integrity), between-network connectivity (segregation), seed-based connectivity of resting-state networks, and global connectivity. Differences between placebo and the active conditions were assessed using repeated-measures ANOVA, followed by post-hoc pairwise t-tests. Changes in voxel-wise seed-based connectivity were correlated with serotonin 2 A receptor density maps. Compared to placebo, all substances reduced integrity in several networks, indicating both common and unique effects. While LSD uniquely reduced integrity in the default-mode network (DMN), the amphetamines, in contrast to our expectations, reduced integrity in more networks than LSD. However, LSD exhibited more pronounced segregation effects, characterized solely by decreases, in contrast to the amphetamines, which also induced increases. Across all substances, seed-based connectivity mostly increased between networks, with LSD demonstrating more pronounced effects than both amphetamines. Finally, while all substances decreased global connectivity in visual areas, compared to placebo, LSD specifically increased global connectivity in the basal ganglia and thalamus. These findings advance our understanding of the distinctive neurobiological effects of psychedelics, prompting further exploration of their therapeutic potential.

2.
Brain ; 146(2): 767-777, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-35875972

RESUMO

Negative symptoms, such as lack of motivation or social withdrawal, are highly prevalent and debilitating in patients with schizophrenia. Underlying mechanisms of negative symptoms are incompletely understood, thereby preventing the development of targeted treatments. We hypothesized that in patients with schizophrenia during psychotic remission, impaired influences of both model-based and model-free reward predictions on decision-making ('reward prediction influence', RPI) underlie negative symptoms. We focused on psychotic remission, because psychotic symptoms might confound reward-based decision-making. Moreover, we hypothesized that impaired model-based/model-free RPIs depend on alterations of both associative striatum dopamine synthesis and storage (DSS) and executive functioning. Both factors influence RPI in healthy subjects and are typically impaired in schizophrenia. Twenty-five patients with schizophrenia with pronounced negative symptoms during psychotic remission and 24 healthy controls were included in the study. Negative symptom severity was measured by the Positive and Negative Syndrome Scale negative subscale, model-based/model-free RPI by the two-stage decision task, associative striatum DSS by 18F-DOPA positron emission tomography and executive functioning by the symbol coding task. Model-free RPI was selectively reduced in patients and associated with negative symptom severity as well as with reduced associative striatum DSS (in patients only) and executive functions (both in patients and controls). In contrast, model-based RPI was not altered in patients. Results provide evidence for impaired model-free reward prediction influence as a mechanism for negative symptoms in schizophrenia as well as for reduced associative striatum dopamine and executive dysfunction as relevant factors. Data suggest potential treatment targets for patients with schizophrenia and pronounced negative symptoms.


Assuntos
Transtornos Psicóticos , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagem , Dopamina , Tomografia Computadorizada por Raios X , Transtornos Psicóticos/diagnóstico por imagem , Recompensa
3.
J Psychiatry Neurosci ; 48(2): E135-E142, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37185319

RESUMO

BACKGROUND: Structural MRI studies in people with first-episode psychosis (FEP) and those in the clinical high-risk (CHR) state have consistently shown volumetric abnormalities that depict changes in the structural complexity of the cortical boundary. The aim of the present study was to employ chaos analysis in the identification of people with psychosis based on the structural complexity of the cortical boundary and subcortical areas. METHODS: We performed chaos analysis of the grey matter distribution on structural MRIs. First, the outer boundary points for each slice in the axial, coronal and sagittal view were calculated for grey matter maps. Next, the distance of each boundary point from the centre of mass in the grey matter was calculated and stored as spatial series, which was further analyzed by extracting the Largest Lyapunov Exponent (lambda [λ]), a feature depicting the structural complexity of the cortical boundary. RESULTS: Structural MRIs were acquired from 77 FEP, 73 CHR and 44 healthy controls. We compared λ brain maps between groups, which resulted in statistically significant differences in all comparisons. By matching the λ values extracted in axial view with the Morlet wavelet, differences on the surface relief are observed between groups. LIMITATIONS: Parameters were selected after experimentation on the examined sample. Investigation of the effectiveness of the method in a larger data set is needed. CONCLUSION: The proposed framework using spatial series verifies diagnosis-relevant features and may contribute to the identification of structural biomarkers for psychosis.


Assuntos
Transtornos Psicóticos , Humanos , Transtornos Psicóticos/diagnóstico por imagem , Encéfalo , Substância Cinzenta/diagnóstico por imagem , Imageamento por Ressonância Magnética , Reconhecimento Psicológico
4.
Cereb Cortex ; 31(12): 5549-5559, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34171095

RESUMO

Several observations suggest an impact of prematurity on the claustrum. First, the claustrum's development appears to depend on transient subplate neurons of intra-uterine brain development, which are affected by prematurity. Second, the claustrum is the most densely connected region of the mammalian forebrain relative to its volume; due to its effect on pre-oligodendrocytes, prematurity impacts white matter connections and thereby the development of sources and targets of such connections, potentially including the claustrum. Third, due to its high connection degree, the claustrum contributes to general cognitive functioning (e.g., selective attention and task switching/maintaining); general cognitive functioning, however, is at risk in prematurity. Thus, we hypothesized altered claustrum structure after premature birth, with these alterations being associated with impaired general cognitive performance in premature born persons. Using T1-weighted and diffusion-weighted magnetic resonance imaging in 70 very preterm/very low-birth-weight (VP/VLBW) born adults and 87 term-born adults, we found specifically increased mean diffusivity in the claustrum of VP/VLBW adults, associated both with low birth weight and at-trend with reduced IQ. This result demonstrates altered claustrum microstructure after premature birth. Data suggest aberrant claustrum development, which is potentially related with aberrant subplate neuron and forebrain connection development of prematurity.


Assuntos
Claustrum , Nascimento Prematuro , Substância Branca , Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Lactente Extremamente Prematuro , Recém-Nascido , Recém-Nascido de muito Baixo Peso/fisiologia , Imageamento por Ressonância Magnética , Gravidez , Nascimento Prematuro/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
5.
Brain ; 143(11): 3495-3505, 2020 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-33155047

RESUMO

Aberrant dopamine function in the dorsal striatum and aberrant intrinsic functional connectivity (iFC) between distinct cortical networks and thalamic nuclei are among the most consistent large-scale brain imaging findings in schizophrenia. A pathophysiological link between these two alterations is suggested by theoretical models based on striatal dopamine's topographic modulation of cortico-thalamic connectivity within cortico-basal-ganglia-thalamic circuits. We hypothesized that aberrant striatal dopamine links topographically with aberrant cortico-thalamic iFC, i.e. aberrant associative striatum dopamine is associated with aberrant iFC between the salience network and thalamus, and aberrant sensorimotor striatum dopamine with aberrant iFC between the auditory-sensorimotor network and thalamus. Nineteen patients with schizophrenia during remission of psychotic symptoms and 19 age- and sex-comparable control subjects underwent simultaneous fluorodihydroxyphenyl-l-alanine PET (18F-DOPA-PET) and resting state functional MRI (rs-fMRI). The influx constant kicer based on 18F-DOPA-PET was used to measure striatal dopamine synthesis capacity; correlation coefficients between rs-fMRI time series of cortical networks and thalamic regions of interest were used to measure iFC. In the salience network-centred system, patients had reduced associative striatum dopamine synthesis capacity, which correlated positively with decreased salience network-mediodorsal-thalamus iFC. This correlation was present in both patients and healthy controls. In the auditory-sensorimotor network-centred system, patients had reduced sensorimotor striatum dopamine synthesis capacity, which correlated positively with increased auditory-sensorimotor network-ventrolateral-thalamus iFC. This correlation was present in patients only. Results demonstrate that reduced striatal dopamine synthesis capacity links topographically with cortico-thalamic intrinsic dysconnectivity in schizophrenia. Data suggest that aberrant striatal dopamine and cortico-thalamic dysconnectivity are pathophysiologically related within dopamine-modulated cortico-basal ganglia-thalamic circuits in schizophrenia.


Assuntos
Córtex Cerebral/metabolismo , Corpo Estriado/metabolismo , Dopamina/metabolismo , Vias Neurais/metabolismo , Esquizofrenia/metabolismo , Tálamo/metabolismo , Adulto , Córtex Cerebral/diagnóstico por imagem , Corpo Estriado/diagnóstico por imagem , Di-Hidroxifenilalanina/análogos & derivados , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Esquizofrenia/diagnóstico por imagem , Tálamo/diagnóstico por imagem
6.
Neuroimage ; 208: 116438, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31811902

RESUMO

Premature birth bears an increased risk for aberrant brain development concerning its structure and function. Cortical complexity (CC) expresses the fractal dimension of the brain surface and changes during neurodevelopment. We hypothesized that CC is altered after premature birth and associated with long-term cognitive development. One-hundred-and-one very premature-born adults (gestational age <32 weeks and/or birth weight <1500 â€‹g) and 111 term-born adults were assessed by structural MRI and cognitive testing at 26 years of age. CC was measured based on MRI by vertex-wise estimation of fractal dimension. Cognitive performance was measured based on Griffiths-Mental-Development-Scale (at 20 months) and Wechsler-Adult-Intelligence-Scales (at 26 years). In premature-born adults, CC was decreased bilaterally in large lateral temporal and medial parietal clusters. Decreased CC was associated with lower gestational age and birth weight. Furthermore, decreased CC in the medial parietal cortices was linked with reduced full-scale IQ of premature-born adults and mediated the association between cognitive development at 20 months and IQ in adulthood. Results demonstrate that CC is reduced in very premature-born adults in temporoparietal cortices, mediating the impact of prematurity on impaired cognitive development. These data indicate functionally relevant long-term alterations in the brain's basic geometry of cortical organization in prematurity.


Assuntos
Córtex Cerebral/anatomia & histologia , Córtex Cerebral/crescimento & desenvolvimento , Desenvolvimento Humano/fisiologia , Recém-Nascido Prematuro/crescimento & desenvolvimento , Inteligência/fisiologia , Adulto , Peso ao Nascer/fisiologia , Córtex Cerebral/diagnóstico por imagem , Feminino , Seguimentos , Fractais , Idade Gestacional , Humanos , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Escalas de Wechsler
7.
Hum Brain Mapp ; 41(18): 5215-5227, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-32845045

RESUMO

Reduced global hippocampus volumes have been demonstrated in premature-born individuals, from newborns to adults; however, it is unknown whether hippocampus subfield (HCSF) volumes are differentially affected by premature birth and how relevant they are for cognitive performance. To address these questions, we investigated magnetic resonance imaging (MRI)-derived HCSF volumes in very premature-born adults, and related them with general cognitive performance in adulthood. We assessed 103 very premature-born (gestational age [GA] <32 weeks and/or birth weight <1,500 g) and 109 term-born individuals with cognitive testing and structural MRI at 26 years of age. HCSFs were automatically segmented based on three-dimensional T1- and T2-weighted sequences and studied both individually and grouped into three functional units, namely hippocampus proper (HP), subicular complex (SC), and dentate gyrus (DG). Cognitive performance was measured using the Wechsler-Adult-Intelligence-Scale (full-scale intelligence quotient [FS-IQ]) at 26 years. We observed bilateral volume reductions for almost all HCSF volumes in premature-born adults and associations with GA and neonatal treatment intensity but not birth weight. Left-sided HP, SC, and DG volumes were associated with adult FS-IQ. Furthermore, left DG volume was a mediator of the association between GA and adult FS-IQ in premature-born individuals. Results demonstrate nonspecifically reduced HCSF volumes in premature-born adults; but specific associations with cognitive outcome highlight the importance of the left DG. Data suggest that specific interventions toward hippocampus function might be promising to lower adverse cognitive effects of prematurity.


Assuntos
Peso ao Nascer/fisiologia , Lateralidade Funcional/fisiologia , Hipocampo/anatomia & histologia , Recém-Nascido de Baixo Peso/fisiologia , Recém-Nascido Prematuro/fisiologia , Inteligência/fisiologia , Adulto , Giro Denteado/anatomia & histologia , Giro Denteado/diagnóstico por imagem , Feminino , Idade Gestacional , Hipocampo/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador , Lactente Extremamente Prematuro/fisiologia , Recém-Nascido , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Escalas de Wechsler
8.
J Psychiatry Neurosci ; 45(3): 214-221, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32167267

RESUMO

Background: Resting-state functional MRI (fMRI) studies commonly report alterations in 3 core networks in obsessive­compulsive disorder (OCD) ­ the frontoparietal network, the default mode network and the salience network ­ defined by functionally connected infraslow oscillations in ongoing brain activity. However, most of these studies observed static functional connectivity in the brains of patients with OCD. Methods: To investigate dynamic functional connectivity alterations and widen the evidence base toward the triple network model in OCD, we performed group-based independent component and sliding time window analyses in 49 patients with OCD and 41 healthy controls. Results: The traditional independent component analysis showed alterations in the left frontoparietal network as well as between the left and right frontoparietal networks in patients with OCD compared with healthy controls. For dynamic functional connectivity, the sliding time window approach revealed peak dysconnectivity between the left and right frontoparietal networks and between the left frontoparietal network and the salience network. Limitations: The number of independent components, noise in the resting-state fMRI images, the heterogeneity of the OCD sample, and comorbidities and medication status in the patients could have biased the results. Conclusion: Disrupted modulation of these intrinsic brain networks may contribute to the pathophysiology of OCD.


Assuntos
Lobo Frontal/diagnóstico por imagem , Transtorno Obsessivo-Compulsivo/diagnóstico por imagem , Lobo Parietal/diagnóstico por imagem , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Feminino , Lobo Frontal/fisiopatologia , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Transtorno Obsessivo-Compulsivo/fisiopatologia , Lobo Parietal/fisiopatologia , Adulto Jovem
9.
Brain ; 142(6): 1813-1826, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31135051

RESUMO

While there is consistent evidence for increased presynaptic dopamine synthesis capacity in the striatum of patients with schizophrenia during psychosis, it is unclear whether this also holds for patients during psychotic remission. This study investigates whether striatal dopamine synthesis capacity is altered in patients with schizophrenia during symptomatic remission of positive symptoms, and whether potential alterations relate to symptoms other than positive, such as cognitive difficulties. Twenty-three patients with schizophrenia in symptomatic remission of positive symptoms according to Andreasen, and 24 healthy controls underwent 18F-DOPA-PET and behavioural-cognitive assessment. Imaging data were analysed with voxel-wise Patlak modelling with cerebellum as reference region, resulting in the influx constant kicer reflecting dopamine synthesis capacity. For the whole striatum and its subdivisions (i.e. limbic, associative, and sensorimotor), averaged regional kicer values were calculated, compared across groups, and correlated with behavioural-cognitive scores, including a mediation analysis. Patients had negative symptoms (Positive and Negative Syndrome Scale-negative 14.13 ± 5.91) and cognitive difficulties, i.e. they performed worse than controls in Trail-Making-Test-B (TMT-B; P = 0.01). Furthermore, kicer was reduced in patients for whole striatum (P = 0.004) and associative (P = 0.002) and sensorimotor subdivisions (P = 0.007). In patients, whole striatum kicer was negatively correlated with TMT-B (rho = -0.42, P = 0.04; i.e. the lower striatal kicer, the worse the cognitive performance). Mediation analysis showed that striatal kicer mediated the group difference in TMT-B. Results demonstrate that patients with schizophrenia in symptomatic remission of positive symptoms have decreased striatal dopamine synthesis capacity, which mediates the disorder's impact on cognitive difficulties. Data suggest that striatal dopamine dysfunction contributes to cognitive difficulties in schizophrenia.


Assuntos
Corpo Estriado/fisiopatologia , Dopamina/biossíntese , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/fisiopatologia , Adulto , Idoso , Corpo Estriado/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neostriado/metabolismo , Neostriado/fisiopatologia , Tomografia por Emissão de Pósitrons/métodos , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/metabolismo , Esquizofrenia/metabolismo
10.
Child Dev ; 91(1): e77-e91, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30291757

RESUMO

This study investigated if crying, sleeping or feeding problems that co-occur (multiple regulatory problems [RPs]) or are persistent predict attention problems and diagnoses of attention deficit hyperactivity disorder (ADHD) in childhood and adulthood. Participants were 342 individuals who were assessed at 5, 20, and 56 months for crying, sleeping, and feeding (RPs) and at 6, 8, and 28 years for ADHD diagnoses, attention problems, and attention span. Infants/toddlers with multiple/persistent RPs had an increased risk of receiving an ADHD diagnosis both in childhood and adulthood compared to those who never had RPs. Multiple/persistent RPs were further associated with a high-decreasing attention problems trajectory from childhood to adulthood. Interventions to alleviate early RPs may prevent the development of attention problems.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/complicações , Choro , Transtornos da Alimentação e da Ingestão de Alimentos/complicações , Transtornos do Sono-Vigília/complicações , Adulto , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Estudos Prospectivos , Autocontrole
11.
Infancy ; 24(5): 768-786, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32677276

RESUMO

Regulatory problems in infancy and toddlerhood have previously been associated with an increased risk of developing attention problems in childhood. We hypothesized that early regulatory problems are associated with attention problems via reduced inhibitory control. This prospective study assessed 1,459 children from birth to 8 years. Crying, feeding, and sleeping problems were assessed at 5 and 20 months via parent interviews and neurological examinations. At 20 months, inhibitory control was tested with a behavioral (snack delay) task. Attention regulation was assessed at 6 and 8 years using multiple instruments and informants. Detrimental effects of crying, feeding, and sleeping problems on attention regulation were partly mediated by children's ability to inhibit unwanted behaviors (ß = -0.04, p = 0.013). Accounting for cognition diminished this indirect effect (ß = -0.01, p = 0.209). Instead, the effects of crying, feeding, and sleeping problems on attention regulation were fully mediated by children's cognitive functioning (ß = -0.10, p < 0.001). These results support that inhibitory control abilities partly mediate effects of crying, feeding, and sleeping problems. However, these effects may be accounted for by children's general cognitive abilities. Early regulatory problems may set infants on a course of under control of behavior into school age, and such trajectories are highly associated with general cognitive development.

14.
BMC Neurosci ; 15: 39, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24742205

RESUMO

BACKGROUND: There appears to be an inconsistency in experimental paradigms used in fMRI research on moral judgments. As stimuli, moral dilemmas or moral statements/ pictures that induce emotional reactions are usually employed; a main difference between these stimuli is the perspective of the participants reflecting first-person (moral dilemmas) or third-person perspective (moral reactions). The present study employed functional magnetic resonance imaging (fMRI) in order to investigate the neural correlates of moral judgments in either first- or third-person perspective. RESULTS: Our results indicate that different neural mechanisms appear to be involved in these perspectives. Although conjunction analysis revealed common activation in the anterior medial prefrontal cortex, third person-perspective elicited unique activations in hippocampus and visual cortex. The common activation can be explained by the role the anterior medial prefrontal cortex may play in integrating different information types and also by its involvement in theory of mind. Our results also indicate that the so-called "actor-observer bias" affects moral evaluation in the third-person perspective, possibly due to the involvement of the hippocampus. We suggest two possible ways in which the hippocampus may support the process of moral judgment: by the engagement of episodic memory and its role in understanding the behaviors and emotions of others. CONCLUSION: We posit that these findings demonstrate that first or third person perspectives in moral cognition involve distinct neural processes, that are important to different aspects of moral judgments. These results are important to a deepened understanding of neural correlates of moral cognition-the so-called "first tradition" of neuroethics, with the caveat that any results must be interpreted and employed with prudence, so as to heed neuroethics "second tradition" that sustains the pragmatic evaluation of outcomes, capabilities and limitations of neuroscientific techniques and technologies.


Assuntos
Artefatos , Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Emoções/fisiologia , Julgamento/fisiologia , Princípios Morais , Adulto , Feminino , Humanos , Masculino , Julgamento Moral Retrospectivo
15.
Schizophr Bull ; 50(5): 1208-1222, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-38577901

RESUMO

BACKGROUND AND HYPOTHESIS: Abnormal thalamic nuclei volumes and their link to cognitive impairments have been observed in schizophrenia. However, whether and how this finding extends to the schizophrenia spectrum is unknown. We hypothesized a distinct pattern of aberrant thalamic nuclei volume across the spectrum and examined its potential associations with cognitive symptoms. STUDY DESIGN: We performed a FreeSurfer-based volumetry of T1-weighted brain MRIs from 137 healthy controls, 66 at-risk mental state (ARMS) subjects, 89 first-episode psychosis (FEP) individuals, and 126 patients with schizophrenia to estimate thalamic nuclei volumes of six nuclei groups (anterior, lateral, ventral, intralaminar, medial, and pulvinar). We used linear regression models, controlling for sex, age, and estimated total intracranial volume, both to compare thalamic nuclei volumes across groups and to investigate their associations with positive, negative, and cognitive symptoms. STUDY RESULTS: We observed significant volume alterations in medial and lateral thalamic nuclei. Medial nuclei displayed consistently reduced volumes across the spectrum compared to controls, while lower lateral nuclei volumes were only observed in schizophrenia. Whereas positive and negative symptoms were not associated with reduced nuclei volumes across all groups, higher cognitive scores were linked to lower volumes of medial nuclei in ARMS. In FEP, cognition was not linked to nuclei volumes. In schizophrenia, lower cognitive performance was associated with lower medial volumes. CONCLUSIONS: Results demonstrate distinct thalamic nuclei volume reductions across the schizophrenia spectrum, with lower medial nuclei volumes linked to cognitive deficits in ARMS and schizophrenia. Data suggest a distinctive trajectory of thalamic nuclei abnormalities along the course of schizophrenia.


Assuntos
Disfunção Cognitiva , Imageamento por Ressonância Magnética , Transtornos Psicóticos , Esquizofrenia , Núcleos Talâmicos , Humanos , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/patologia , Feminino , Masculino , Adulto , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/patologia , Transtornos Psicóticos/fisiopatologia , Núcleos Talâmicos/diagnóstico por imagem , Núcleos Talâmicos/patologia , Adulto Jovem , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/patologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/fisiopatologia , Adolescente
16.
Brain Sci ; 14(7)2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-39061410

RESUMO

Deficits in memory performance have been linked to a wide range of neurological and neuropsychiatric conditions. While many studies have assessed the memory impacts of individual conditions, this study considers a broader perspective by evaluating how memory recall is differentially associated with nine common neuropsychiatric conditions using data drawn from 55 international studies, aggregating 15,883 unique participants aged 15-90. The effects of dementia, mild cognitive impairment, Parkinson's disease, traumatic brain injury, stroke, depression, attention-deficit/hyperactivity disorder (ADHD), schizophrenia, and bipolar disorder on immediate, short-, and long-delay verbal learning and memory (VLM) scores were estimated relative to matched healthy individuals. Random forest models identified age, years of education, and site as important VLM covariates. A Bayesian harmonization approach was used to isolate and remove site effects. Regression estimated the adjusted association of each clinical group with VLM scores. Memory deficits were strongly associated with dementia and schizophrenia (p < 0.001), while neither depression nor ADHD showed consistent associations with VLM scores (p > 0.05). Differences associated with clinical conditions were larger for longer delayed recall duration items. By comparing VLM across clinical conditions, this study provides a foundation for enhanced diagnostic precision and offers new insights into disease management of comorbid disorders.

17.
Schizophr Bull ; 49(6): 1530-1541, 2023 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-37606273

RESUMO

BACKGROUND AND HYPOTHESIS: The cholinergic system is altered in schizophrenia. Particularly, patients' volumes of basal-forebrain cholinergic nuclei (BFCN) are lower and correlated with attentional deficits. It is unclear, however, if and how BFCN changes and their link to cognitive symptoms extend across the schizophrenia spectrum, including individuals with at-risk mental state for psychosis (ARMS) or during first psychotic episode (FEP). STUDY DESIGN: To address this question, we assessed voxel-based morphometry (VBM) of structural magnetic resonance imaging data of anterior and posterior BFCN subclusters as well as symptom ratings, including cognitive, positive, and negative symptoms, in a large multi-site dataset (n = 4) comprising 68 ARMS subjects, 98 FEP patients (27 unmedicated and 71 medicated), 140 patients with established schizophrenia (SCZ; medicated), and 169 healthy controls. RESULTS: In SCZ, we found lower VBM measures for the anterior BFCN, which were associated with the anticholinergic burden of medication and correlated with patients' cognitive deficits. In contrast, we found larger VBM measures for the posterior BFCN in FEP, which were driven by unmedicated patients and correlated at-trend with cognitive deficits. We found no BFCN changes in ARMS. Altered VBM measures were not correlated with positive or negative symptoms. CONCLUSIONS: Results demonstrate complex (posterior vs. anterior BFCN) and non-linear (larger vs. lower VBM) differences in BFCN across the schizophrenia spectrum, which are specifically associated both with medication, including its anticholinergic burden, and cognitive symptoms. Data suggest an altered trajectory of BFCN integrity in schizophrenia, influenced by medication and relevant for cognitive symptoms.


Assuntos
Transtornos Psicóticos , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/tratamento farmacológico , Esquizofrenia/patologia , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/tratamento farmacológico , Prosencéfalo , Imageamento por Ressonância Magnética/métodos , Antagonistas Colinérgicos/efeitos adversos , Cognição
18.
Artigo em Inglês | MEDLINE | ID: mdl-37532129

RESUMO

BACKGROUND: While the exploration of serotonergic psychedelics as psychiatric medicines deepens, so does the pressure to better understand how these compounds act on the brain. METHODS: We used a double-blind, placebo-controlled, crossover design and administered lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), and d-amphetamine in 25 healthy participants. By using spectral dynamic causal modeling, we mapped substance-induced changes in effective connectivity between the thalamus and different cortex types (unimodal vs. transmodal) derived from a previous study with resting-state functional magnetic resonance imaging data. Due to the distinct pharmacological modes of action of the 3 substances, we were able to investigate specific effects mainly driven by different neurotransmitter systems on thalamocortical and corticothalamic interactions. RESULTS: Compared with placebo, all 3 substances increased the effective connectivity from the thalamus to specific unimodal cortices, whereas the influence of these cortices on the thalamus was reduced. These results indicate increased bottom-up and decreased top-down information flow between the thalamus and some unimodal cortices. However, for the amphetamines, we found the opposite effects when examining the effective connectivity with transmodal cortices, including parts of the salience network. Intriguingly, LSD increased the effective connectivity from the thalamus to both unimodal and transmodal cortices, indicating a breach in the hierarchical organization of ongoing brain activity. CONCLUSIONS: The results advance our knowledge about the action of psychedelics on the brain and refine current models aiming to explain the underlying neurobiological processes.

19.
bioRxiv ; 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-36712107

RESUMO

Investigators in neuroscience have turned to Big Data to address replication and reliability issues by increasing sample sizes, statistical power, and representativeness of data. These efforts unveil new questions about integrating data arising from distinct sources and instruments. We focus on the most frequently assessed cognitive domain - memory testing - and demonstrate a process for reliable data harmonization across three common measures. We aggregated global raw data from 53 studies totaling N = 10,505 individuals. A mega-analysis was conducted using empirical bayes harmonization to remove site effects, followed by linear models adjusting for common covariates. A continuous item response theory (IRT) model estimated each individual's latent verbal learning ability while accounting for item difficulties. Harmonization significantly reduced inter-site variance while preserving covariate effects, and our conversion tool is freely available online. This demonstrates that large-scale data sharing and harmonization initiatives can address reproducibility and integration challenges across the behavioral sciences.

20.
Front Psychiatry ; 13: 909961, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35873225

RESUMO

The basal forebrain cholinergic nuclei (BFCN) provide the main cholinergic input to prefrontal cortices, the hippocampi, and amygdala. These structures are highly relevant for the regulation and maintenance of many cognitive functions, such as attention and memory. In vivo neuroimaging studies reported alterations of the cholinergic system in psychotic disorders. Particularly, a downregulation of nicotinic and muscarinic acetylcholine receptors has been found. Crucially, such alterations in neurotransmission have been associated with cognitive impairments and positive and negative symptoms. Recent pharmacological studies support these findings, as they demonstrated an association between the manipulation of cholinergic transmission and an attenuation in symptom severity. Targeting acetylcholine receptors has therefore become a focus for the development of novel psychopharmacological drugs. However, many open questions remain. For instance, it remains elusive what causes such alterations in neurotransmission. While evidence supports the idea that BFCN structural integrity is altered in schizophrenia, it remains to be determined whether this is also present in other psychotic disorders. Furthermore, it is unclear when throughout the course of the disorder these alterations make their appearance and whether they reflect changes in the BFCN alone or rather aberrant interactions between the BFCN and other brain areas. In this review, the specific role of the BFCN and their projections are discussed from a neuroimaging perspective and with a focus on psychotic disorders alongside future directions. These directions set the stage for the development of new treatment targets for psychotic disorders.

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