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1.
Mol Syst Biol ; 20(8): 972-995, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38907068

RESUMO

Mass spectrometry has revolutionized cell signaling research by vastly simplifying the analysis of many thousands of phosphorylation sites in the human proteome. Defining the cellular response to perturbations is crucial for further illuminating the functionality of the phosphoproteome. Here we describe µPhos ('microPhos'), an accessible phosphoproteomics platform that permits phosphopeptide enrichment from 96-well cell culture and small tissue amounts in <8 h total processing time. By greatly minimizing transfer steps and liquid volumes, we demonstrate increased sensitivity, >90% selectivity, and excellent quantitative reproducibility. Employing highly sensitive trapped ion mobility mass spectrometry, we quantify ~17,000 Class I phosphosites in a human cancer cell line using 20 µg starting material, and confidently localize ~6200 phosphosites from 1 µg. This depth covers key signaling pathways, rendering sample-limited applications and perturbation experiments with hundreds of samples viable. We employ µPhos to study drug- and time-dependent response signatures in a leukemia cell line, and by quantifying 30,000 Class I phosphosites in the mouse brain we reveal distinct spatial kinase activities in subregions of the hippocampal formation.


Assuntos
Fosfopeptídeos , Fosfoproteínas , Proteômica , Proteômica/métodos , Humanos , Animais , Camundongos , Fosfoproteínas/metabolismo , Fosforilação , Linhagem Celular Tumoral , Fosfopeptídeos/metabolismo , Fosfopeptídeos/análise , Espectrometria de Massas/métodos , Transdução de Sinais , Proteoma/metabolismo , Reprodutibilidade dos Testes , Hipocampo/metabolismo , Hipocampo/citologia
2.
Cerebellum ; 23(4): 1521-1529, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38363498

RESUMO

Cerebellar atrophy is the neuropathological hallmark of most ataxias. Hence, quantifying the volume of the cerebellar grey and white matter is of great interest. In this study, we aim to identify volume differences in the cerebellum between spinocerebellar ataxia type 1 (SCA1), SCA3 and SCA6 as well as multiple system atrophy of cerebellar type (MSA-C). Our cross-sectional data set comprised mutation carriers of SCA1 (N=12), SCA3 (N=62), SCA6 (N=14), as well as MSA-C patients (N=16). Cerebellar volumes were obtained from T1-weighted magnetic resonance images. To compare the different atrophy patterns, we performed a z-transformation and plotted the intercept of each patient group's model at the mean of 7 years of ataxia duration as well as at the mean ataxia severity of 14 points in the SARA sum score. In addition, we plotted the extrapolation at ataxia duration of 0 years as well as 0 points in the SARA sum score. Patients with MSA-C demonstrated the most pronounced volume loss, particularly in the cerebellar white matter, at the late time intercept. Patients with SCA6 showed a pronounced volume loss in cerebellar grey matter with increasing ataxia severity compared to all other patient groups. MSA-C, SCA1 and SCA3 showed a prominent atrophy of the cerebellar white matter. Our results (i) confirmed SCA6 being considered as a pure cerebellar grey matter disease, (ii) emphasise the involvement of cerebellar white matter in the neuropathology of SCA1, SCA3 and MSA-C, and (iii) reflect the rapid clinical progression in MSA-C.


Assuntos
Cerebelo , Imageamento por Ressonância Magnética , Humanos , Masculino , Feminino , Cerebelo/patologia , Cerebelo/diagnóstico por imagem , Pessoa de Meia-Idade , Adulto , Estudos Transversais , Idoso , Índice de Gravidade de Doença , Ataxias Espinocerebelares/diagnóstico por imagem , Ataxias Espinocerebelares/patologia , Ataxias Espinocerebelares/genética , Atrofia/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Tamanho do Órgão , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia
3.
Mol Cell Biochem ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009935

RESUMO

BCR::ABL1 inhibitors, the treatment of choice for the majority of patients with chronic myeloid leukaemia (CML), can cause vascular side effects that vary between agents. The exact underlying mechanisms are still poorly understood, but the vascular endothelium has been proposed as a site of origin. The present study investigates the effects of three BCR::ABL1 inhibitors, ponatinib, nilotinib and imatinib, on angiogenesis and signalling in human endothelial cells in response to vascular endothelial growth factor (VEGF). The experiments were performed in endothelial cells isolated from human umbilical veins. After exposure to imatinib, ponatinib and nilotinib, the angiogenic capacity of endothelial cells was assessed in spheroid assays. VEGF-induced signalling pathways were examined in Western blotting experiments using different specific antibodies. RNAi technology was used to downregulate proteins of interest. Intracellular cGMP levels were measured by ELISA. Imatinib had no effect on endothelial function. Ponatinib inhibited VEGF-induced sprouting, while nilotinib increased spontaneous and VEGF-stimulated angiogenesis. These effects did not involve wild-type ABL1 or ABL2, as siRNA-mediated knockdown of these kinases did not affect angiogenesis and VEGF signalling. Consistent with their effects on sprouting, ponatinib and nilotinib affected angiogenic pathways in opposite directions. While ponatinib inhibited VEGF-induced signalling and cGMP formation, nilotinib activated angiogenic signalling, in particular phosphorylation of extracellular signal-regulated kinase 1/2 (Erk1/2). The latter occurred in an epidermal growth factor receptor (EGFR)-dependent manner possibly via suppressing Fyn-related kinase (FRK), a negative regulator of EGFR signalling. Both, pharmacological inhibition of Erk1/2 or EGFR suppressed nilotinib-induced angiogenic sprouting. These results support the notion that the vascular endothelium is a site of action of BCR::ABL1 inhibitors from which side effects may arise, and that the different vascular toxicity profiles of BCR::ABL1 inhibitors may be due to their different actions at the molecular level. In addition, the as yet unknown pro-angiogenic effect of nilotinib should be considered in the treatment of patients with comorbidities associated with pathological angiogenesis, such as ocular disease, arthritis or obesity.

4.
J Neurooncol ; 168(2): 333-343, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38696050

RESUMO

PURPOSE: To benchmark palliative care practices in neurooncology centers across Germany, evaluating the variability in palliative care integration, timing, and involvement in tumor board discussions. This study aims to identify gaps in care and contribute to the discourse on optimal palliative care strategies. METHODS: A survey targeting both German Cancer Society-certified and non-certified university neurooncology centers was conducted to explore palliative care frameworks and practices for neurooncological patients. The survey included questions on palliative care department availability, involvement in tumor boards, timing of palliative care integration, and use of standardized screening tools for assessing palliative burden and psycho-oncological distress. RESULTS: Of 57 centers contacted, 46 responded (81% response rate). Results indicate a dedicated palliative care department in 76.1% of centers, with palliative specialists participating in tumor board discussions at 34.8% of centers. Variability was noted in the initiation of palliative care, with early integration at the diagnosis stage in only 30.4% of centers. The survey highlighted a significant lack of standardized spiritual care assessments and minimal use of advanced care planning. Discrepancies were observed in the documentation and treatment of palliative care symptoms and social complaints, underscoring the need for comprehensive care approaches. CONCLUSION: The study highlights a diverse landscape of palliative care provision within German neurooncology centers, underscoring the need for more standardized practices and early integration of palliative care. It suggests the necessity for standardized protocols and guidelines to enhance palliative care's quality and uniformity, ultimately improving patient-centered care in neurooncology.


Assuntos
Benchmarking , Cuidados Paliativos , Humanos , Cuidados Paliativos/normas , Alemanha , Oncologia/normas , Inquéritos e Questionários , Neoplasias Encefálicas/terapia , Padrões de Prática Médica/normas , Padrões de Prática Médica/estatística & dados numéricos
6.
Leukemia ; 38(2): 235-249, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38238443

RESUMO

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome driven by pathologic activation of cytotoxic T-lymphocytes and macrophages. Despite advances in diagnostics and management, adult patients with lymphoma-associated HLH (LA-HLH) harbor particularly poor prognosis and optimal treatment remains challenging. As systematic data on LA-HLH are scarce, we aimed to synthesize research evidence by thorough analysis of the published literature in PubMed (MEDLINE-database) within the context of a scoping review. Of 595 search results, 132 articles providing information on 542 patients were reviewed and analyzed. Median patient age was 60 years (range, 18-98) with male predominance (62.7%). B- and T-NHL were equally represented (45.6% and 45.2%), Hodgkin's lymphoma was reported in 8.9% of the cases. The majority of patients (91.6%) presented in Ann-Arbor-Stages III and IV, and bone marrow infiltration was observed in a significant proportion of patients (61.5%). Soluble CD25 levels were markedly elevated (median 10,000 U/ml), with levels beyond 10,000 U/ml indicating unfavorable prognosis for 30-day and overall survival. 66.8% of the patients died after median 5.1 months. LA-HLH remains a clinical challenge requiring specialized management. Timely diagnosis and appropriate lymphoma-specific treatment are of utmost importance to enhance patient outcomes.


Assuntos
Linfo-Histiocitose Hemofagocítica , Linfoma , Adulto , Humanos , Masculino , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/etiologia , Linfo-Histiocitose Hemofagocítica/patologia , Linfoma/complicações , Linfoma/diagnóstico , Prognóstico , Macrófagos/patologia , Medula Óssea/patologia
7.
Sci Rep ; 14(1): 7761, 2024 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-38565603

RESUMO

Prognostic factors for overall survival (OS), percutaneous endoscopic gastrostomy (PEG) dependency, and long-term speech rehabilitation via voice prosthesis (VP) after laryngectomy for laryngeal or hypopharyngeal cancer were investigated in a retrospective population-based study in Thuringia, Germany. A total of 617 patients (68.7% larynx; hypopharynx; 31.3%; 93.7% men; median age 62 years; 66.0% stage IV) from 2001 to 2020 were included. Kaplan-Meier and Cox multivariable regression analyses were performed. 23.7% of patients received a PEG. 74.7% received a VP. Median OS was 131 months. Independent factors for lower OS were stage IV (compared to stage II; hazard ratio [HR] = 3.455; confidence interval [CI] 1.395-8.556) and laryngectomy for a recurrent disease (HR = 1.550; CI 1.078-2.228). Median time to PEG removal was 7 months. Prior partial surgery before laryngectomy showed a tendency for independent association for later PEG removal (HR = 1.959; CI 0.921-4.167). Postoperative aspiration needing treatment was an independent risk factor (HR = 2.679; CI 1.001-7.167) for later definitive VP removal. Laryngectomy continuously plays an important role in a curative daily routine treatment setting of advanced laryngeal or hypopharyngeal cancer in Germany. Long-term dependency on nutrition via PEG is an important issue, whereas use of VP is a stable long-term measure for voice rehabilitation.


Assuntos
Neoplasias Hipofaríngeas , Neoplasias Laríngeas , Laringe , Masculino , Humanos , Pessoa de Meia-Idade , Feminino , Laringectomia , Estudos Retrospectivos , Neoplasias Hipofaríngeas/cirurgia , Neoplasias Laríngeas/cirurgia , Laringe/cirurgia , Resultado do Tratamento
8.
Obes Sci Pract ; 10(1): e734, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38259353

RESUMO

Background: There are established links between the accumulation of body fat as visceral adipose tissue (VAT) and the risk of developing obesity-associated metabolic disease. Previous studies have suggested that levels of intake of specific foods and nutrients are associated with VAT accumulation after accounting for total energy intake. Objective: This study assessed associations between a priori selected dietary factors on VAT quantified using abdominal magnetic resonance imaging. Methods: The cross-sectional Multiethnic Cohort Adiposity Phenotype Study included n = 395 White, n = 274 Black, n = 269 Native Hawaiian, n = 425 Japanese American and n = 358 Latino participants (mean age = 69 years ± 3 SD). Participants were enrolled stratified on sex, race, ethnicity and body mass index. General linear models were used to estimate the mean VAT area (cm2) for participants categorized into quartiles based on their dietary intake of selected foods/nutrients adjusting for age, sex, racial and ethnic groups, the total percentage fat from whole-body dual energy X-ray absorptiometry and total energy. Results: There were significant inverse associations with VAT for dietary intake of total vegetables, total fruits (including juice), cereals, whole grains, calcium, copper and dietary fiber (p-trend ≤0.04). Positive trends were observed for VAT for participants who reported higher intake of potatoes, total fat and saturated fatty acids (SFA) (p-trend ≤0.02). Foods/nutrients that met the multiple testing significance threshold were total fruits, whole grains, copper, dietary fiber and SFA intake. Conclusions: These results highlight foods and nutrients including SFA, total fruit, whole grains, fiber and copper as potential candidates for future research to inform dietary guidelines for the prevention of chronic disease among older adults.

9.
eNeuro ; 11(2)2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38176906

RESUMO

Functional brain imaging studies in humans suggest involvement of the cerebellum in fear conditioning but do not allow conclusions about the functional significance. The main aim of the present study was to examine whether patients with cerebellar degeneration show impaired fear conditioning and whether this is accompanied by alterations in cerebellar cortical activations. To this end, a 2 d differential fear conditioning study was conducted in 20 cerebellar patients and 21 control subjects using a 7 tesla (7 T) MRI system. Fear acquisition and extinction training were performed on day 1, followed by recall on day 2. Cerebellar patients learned to differentiate between the CS+ and CS-. Acquisition and consolidation of learned fear, however, was slowed. Additionally, extinction learning appeared to be delayed. The fMRI signal was reduced in relation to the prediction of the aversive stimulus and altered in relation to its unexpected omission. Similarly, mice with cerebellar cortical degeneration (spinocerebellar ataxia type 6, SCA6) were able to learn the fear association, but retrieval of fear memory was reduced. In sum, cerebellar cortical degeneration led to mild abnormalities in the acquisition of learned fear responses in both humans and mice, particularly manifesting postacquisition training. Future research is warranted to investigate the basis of altered fMRI signals related to fear learning.


Assuntos
Mapeamento Encefálico , Condicionamento Clássico , Humanos , Animais , Camundongos , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Medo/fisiologia , Aprendizagem , Imageamento por Ressonância Magnética
10.
Biol Psychiatry ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39029777

RESUMO

BACKGROUND: Chronic stress significantly contributes to mood- and anxiety disorders. Previous data suggest a correlative connection between vitamin B12 supplementation, depression, and stress resilience. However, the underlying mechanisms are still poorly understood. METHODS: Using the chronic variable stress mouse model coupled with RNA-sequencing, we determined vitamin B12-induced transcriptional changes related to stress resilience. By viral-mediated gene transfer and in vivo epigenome editing, we reveal a functional pathway linking vitamin B12, DNA methylation, and depressive-like symptoms. RESULTS: We identified Transthyretin (Ttr) as a sex-specific key target of vitamin B12 in chronic stress. Accordingly, TTR expression was increased postmortem in the prefrontal cortex of male, but not female, depressed patients. Virally altered Ttr in the prefrontal cortex functionally contributed to stress- and depression-related behaviors, changes in dendritic spine morphology, and gene expression. In stressed mice, vitamin B12 reduced DNAme in the Ttr promoter region. Importantly, using in vivo epigenome editing to alter DNAme in the brains of living mice for the first time, we establish a direct causal link between DNAme on Ttr and stress-associated behaviors. DISCUSSION: Using state-of-the-art techniques, this study uncovers a mechanistic link between vitamin B12 supplementation, Ttr, and markers of chronic stress and depression, encouraging further studies into dietary interventions for mood disorders.

11.
Leuk Res ; 139: 107481, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38484432

RESUMO

The BYOND study evaluated the efficacy and safety of bosutinib 500 mg once daily in patients with chronic myeloid leukemia (CML) resistant/intolerant to prior tyrosine kinase inhibitors (TKIs). These post-hoc analyses assessed the efficacy and safety of bosutinib by resistance or intolerance to prior TKIs (imatinib-resistant vs dasatinib/nilotinib-resistant vs TKI-intolerant), and cross-intolerance between bosutinib and prior TKIs (imatinib, dasatinib, nilotinib), in patients with Philadelphia chromosome-positive chronic phase CML. Data are reported after ≥3 years' follow-up. Of 156 patients with Philadelphia chromosome-positive chronic phase CML, 53 were imatinib-resistant, 29 dasatinib/nilotinib-resistant, and 74 intolerant to all prior TKIs; cumulative complete cytogenetic response rates at any time were 83.7%, 61.5%, and 86.8%, and cumulative major molecular response rates at any time were 72.9%, 40.7%, and 82.4%, respectively. Of 141, 95, and 79 patients who received prior imatinib, dasatinib, and nilotinib, 64 (45.4%), 71 (74.7%), and 60 (75.9%) discontinued the respective TKI due to intolerance; of these, 2 (3.1%), 5 (7.0%), and 0 had cross-intolerance with bosutinib. The response rates observed in TKI-resistant and TKI-intolerant patients, and low cross-intolerance between bosutinib and prior TKIs, further support bosutinib use for patients with Philadelphia chromosome-positive chronic phase CML resistant/intolerant to prior TKIs. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02228382.


Assuntos
Compostos de Anilina , Antineoplásicos , Leucemia Mieloide de Fase Crônica , Nitrilas , Quinolinas , Humanos , Mesilato de Imatinib/efeitos adversos , Dasatinibe/efeitos adversos , Antineoplásicos/efeitos adversos , Cromossomo Filadélfia , Inibidores de Proteínas Quinases/efeitos adversos , Pirimidinas , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Resposta Patológica Completa
12.
Leukemia ; 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39164407

RESUMO

This final analysis from the phase 4 BYOND trial reports outcomes with bosutinib in patients with previously treated chronic myeloid leukemia (CML); 163 patients with CML resistant/intolerant to previous tyrosine kinase inhibitors received bosutinib (starting dose: 500 mg QD). At study completion (median follow-up, 47.8 months), 48.1% (n = 75/156) of patients with Philadelphia chromosome-positive chronic phase CML were still receiving treatment. Among evaluable patients, 71.8% (95% CI, 63.9-78.9) and 59.7% (95% CI, 51.4-67.7) attained or maintained major molecular response (MMR) and molecular response (MR)4, respectively, at any time on treatment. The majority of patients achieved a deeper molecular response relative to baseline while on bosutinib. Kaplan-Meier probabilities (95% CI) of maintaining MMR and MR4 at 36 months were 87.2% (78.0-92.7) and 80.7% (69.4-88.1), respectively. At 48 months, the Kaplan-Meier overall survival rate was 88.3% (95% CI, 81.8-92.6); there were 17 deaths, including 2 that were considered CML related. Long-term adverse events (AEs) were consistent with the known safety profile of bosutinib, and no new safety issues were identified. The management of AEs through dose reduction maintained efficacy while improving tolerability. These results support the use of bosutinib in patients with previously treated CML.ClinicalTrials.gov, NCT02228382.

13.
PLoS One ; 19(7): e0306606, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39024224

RESUMO

BACKGROUND: We previously developed a prediction score for MRI-quantified abdominal visceral adipose tissue (VAT) based on concurrent measurements of height, body mass index (BMI), and nine blood biomarkers, for optimal performance in five racial/ethnic groups. Here we evaluated the VAT score for prediction of future VAT and examined if enhancement with additional biomarkers, lifestyle behavior information, and medical history improves the prediction. METHODS: We examined 500 participants from the Multiethnic Cohort (MEC) with detailed data (age 50-66) collected 10 years prior to their MRI assessment of VAT. We generated three forecasted VAT prediction models: first by applying the original VAT equation to the past data on the predictors ("original"), second by refitting the past data on anthropometry and biomarkers ("refit"), and third by building a new prediction model based on the past data enhanced with lifestyle and medical history ("enhanced"). We compared the forecasted prediction scores to future VAT using the coefficient of determination (R2). In independent nested case-control data in MEC, we applied the concurrent and forecasted VAT models to assess association of the scores with subsequent incident breast cancer (950 pairs) and colorectal cancer (831 pairs). RESULTS: Compared to the VAT prediction by the concurrent VAT score (R2 = 0.70 in men, 0.68 in women), the forecasted original VAT score (R2 = 0.54, 0.48) performed better than past anthropometry alone (R2 = 0.47, 0.40) or two published scores (VAI, METS-VF). The forecasted refit (R2 = 0.61, 0.51) and enhanced (R2 = 0.62, 0.55) VAT scores each showed slight improvements. Similar to the concurrent VAT score, the forecasted VAT scores were associated with breast cancer, but not colorectal cancer. Both the refit score (adjusted OR for tertile 3 vs. 1 = 1.27; 95% CI: 1.00-1.62) and enhanced score (1.27; 0.99-1.62) were associated with breast cancer independently of BMI. CONCLUSIONS: Predicted VAT from midlife data can be used as a surrogate to assess the effect of VAT on incident diseases associated with obesity, as illustrated for postmenopausal breast cancer.


Assuntos
Adiposidade , Gordura Intra-Abdominal , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Massa Corporal , Estudos de Casos e Controles , Estudos de Coortes , Etnicidade , Gordura Intra-Abdominal/diagnóstico por imagem , Imageamento por Ressonância Magnética , Neoplasias/diagnóstico por imagem , Grupos Raciais
14.
Leukemia ; 38(5): 1072-1080, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38548962

RESUMO

Blast phase (BP) of chronic myeloid leukemia (CML) still represents an unmet clinical need with a dismal prognosis. Due to the rarity of the condition and the heterogeneity of the biology and clinical presentation, prospective trials and concise treatment recommendations are lacking. Here we present the analysis of the European LeukemiaNet Blast Phase Registry, an international collection of the clinical presentation, treatment and outcome of blast phases which had been diagnosed in CML patients after 2015. Data reveal the expected heterogeneity of the entity, lacking a clear treatment standard. Outcomes remain dismal, with a median overall survival of 23.8 months (median follow up 27.8 months). Allogeneic stem cell transplantation (alloSCT) increases the rate of deep molecular responses. De novo BP and BP evolving from a previous CML do show slightly different features, suggesting a different biology between the two entities. Data show that outside clinical trials and in a real-world setting treatment of blast phase is individualized according to disease- and patient-related characteristics, with the aim of blast clearance prior to allogeneic stem cell transplantation. AlloSCT should be offered to all patients eligible for this procedure.


Assuntos
Crise Blástica , Leucemia Mielogênica Crônica BCR-ABL Positiva , Sistema de Registros , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Crise Blástica/patologia , Gerenciamento Clínico , Europa (Continente) , Seguimentos , Transplante de Células-Tronco Hematopoéticas/métodos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Prognóstico , Taxa de Sobrevida , Transplante Homólogo , Resultado do Tratamento , Idoso de 80 Anos ou mais
15.
Front Hum Neurosci ; 17: 1328283, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38264350

RESUMO

Fear is a vital defense mechanism to potential threats, which is influenced by the cerebellum. While the cerebellum's role in acquiring fear responses is well understood, limited knowledge exists about its involvement in fear extinction. In this study, we investigated the effects of cerebellar theta band transcranial alternating current stimulation (ctACS) administered during fear extinction training, based on previous evidence from animal studies suggesting a role of cerebellar theta oscillations in associative memory formation. To this end, thirty-seven healthy right-handed male participants were recruited for a two-day differential fear renewal paradigm. On day 1, they underwent acquisition training in context A followed by extinction training in context B. On day 2, recall was tested in contexts A and B. One group of participants received ctACS in the theta band (6 Hz) during extinction training. The other group received sham ctACS. Although both groups demonstrated the ability to recall previously learned fear and distinguish between low and high threat stimuli, no significant differences were observed between the ctACS and sham groups, indicating that ctACS at this theta frequency range did not impact extinction and recall of previously acquired fear in this study. Nevertheless, using ctACS could still be useful in future research, including brain imaging studies, to better understand how the cerebellum is involved in fear and extinction processes.

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