Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
J Med Syst ; 48(1): 45, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38652327

RESUMO

In medical and biomedical education, traditional teaching methods often struggle to engage students and promote critical thinking. The use of AI language models has the potential to transform teaching and learning practices by offering an innovative, active learning approach that promotes intellectual curiosity and deeper understanding. To effectively integrate AI language models into biomedical education, it is essential for educators to understand the benefits and limitations of these tools and how they can be employed to achieve high-level learning outcomes.This article explores the use of AI language models in biomedical education, focusing on their application in both classroom teaching and learning assignments. Using the SOLO taxonomy as a framework, I discuss strategies for designing questions that challenge students to exercise critical thinking and problem-solving skills, even when assisted by AI models. Additionally, I propose a scoring rubric for evaluating student performance when collaborating with AI language models, ensuring a comprehensive assessment of their learning outcomes.AI language models offer a promising opportunity for enhancing student engagement and promoting active learning in the biomedical field. Understanding the potential use of these technologies allows educators to create learning experiences that are fit for their students' needs, encouraging intellectual curiosity and a deeper understanding of complex subjects. The application of these tools will be fundamental to provide more effective and engaging learning experiences for students in the future.


Assuntos
Inteligência Artificial , Humanos , Aprendizagem Baseada em Problemas/métodos , Educação Médica/métodos , Avaliação Educacional/métodos
2.
BMC Biol ; 20(1): 283, 2022 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-36527001

RESUMO

BACKGROUND: Like most living organisms, the fruit fly Drosophila melanogaster exhibits strong and diverse behavioural reactions to light. Drosophila is a diurnal animal that displays both short- and long-term responses to light, important for, instance, in avoidance and light wavelength preference, regulation of eclosion, courtship, and activity, and provides an important model organism for understanding the regulation of circadian rhythms both at molecular and circuit levels. However, the assessment and comparison of light-based behaviours is still a challenge, mainly due to the lack of a standardised platform to measure behaviour and different protocols created across studies. Here, we describe the Drosophila Interactive System for Controlled Optical manipulations (DISCO), a low-cost, automated, high-throughput device that records the flies' activity using infrared beams while performing LED light manipulations. RESULTS: To demonstrate the effectiveness of this tool and validate its potential as a standard platform, we developed a number of distinct assays, including measuring the locomotor response of flies exposed to sudden darkness (lights-off) stimuli. Both white-eyed and red-eyed wild-type flies exhibit increased activity after the application of stimuli, while no changes can be observed in Fmr1 null allele flies, a model of fragile X syndrome. Next, to demonstrate the use of DISCO in long-term protocols, we monitored the circadian rhythm of the flies for 48 h while performing an alcohol preference test. We show that increased alcohol consumption happens intermittently throughout the day, especially in the dark phases. Finally, we developed a feedback-loop algorithm to implement a place preference test based on the flies' innate aversion to blue light and preference for green light. We show that both white-eyed and red-eyed wild-type flies were able to learn to avoid the blue-illuminated zones. CONCLUSIONS: Our results demonstrate the versatility of DISCO for a range of protocols, indicating that this platform can be used in a variety of ways to study light-dependent behaviours in flies.


Assuntos
Proteínas de Drosophila , Drosophila melanogaster , Animais , Drosophila melanogaster/fisiologia , Ritmo Circadiano/fisiologia , Drosophila/fisiologia , Atividade Motora/fisiologia , Visão Ocular , Proteína do X Frágil da Deficiência Intelectual
3.
Learn Mem ; 28(10): 371-389, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34526382

RESUMO

Remembering is not a static process: When retrieved, a memory can be destabilized and become prone to modifications. This phenomenon has been demonstrated in a number of brain regions, but the neuronal mechanisms that rule memory destabilization and its boundary conditions remain elusive. Using two distinct computational models that combine Hebbian plasticity and synaptic downscaling, we show that homeostatic plasticity can function as a destabilization mechanism, accounting for behavioral results of protein synthesis inhibition upon reactivation with different re-exposure times. Furthermore, by performing systematic reviews, we identify a series of overlapping molecular mechanisms between memory destabilization and synaptic downscaling, although direct experimental links between both phenomena remain scarce. In light of these results, we propose a theoretical framework where memory destabilization can emerge as an epiphenomenon of homeostatic adaptations prompted by memory retrieval.


Assuntos
Consolidação da Memória , Memória , Encéfalo , Rememoração Mental , Plasticidade Neuronal
4.
J Transl Med ; 19(1): 133, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33789668

RESUMO

BACKGROUND: Migraine and depression are highly prevalent and partly overlapping disorders that cause strong limitations in daily life. Patients tend to respond poorly to the therapies available for these diseases. OnabotulinumtoxinA has been proven to be an effective treatment for both migraine and depression. While many studies have addressed the effect of onabotulinumtoxinA in migraine or depression separately, a growing body of evidence suggests beneficial effects also for patients comorbid with migraine and depression. The current meta-analysis systematically investigates to what extent onabotulinumtoxinA is efficient in migraineurs with depression. METHODS: A systematic literature search was performed based on PubMed, Scopus and Web of Science from the earliest date till October [Formula: see text], 2020. Mean, standard deviation (SD) and sample size have been used to evaluate improvement in depressive symptoms and migraine using random-effects empirical Bayes model. RESULTS: Our search retrieved 259 studies, eight of which met the inclusion criteria. OnabotulinumtoxinA injections administered to patients with both chronic migraine and major depressive disorder led to mean reduction of [Formula: see text] points (CI [[Formula: see text]], [Formula: see text]) in the BDI scale, of [Formula: see text] points (CI [[Formula: see text]], [Formula: see text]) in the BDI-II scale and of [Formula: see text] points (CI [[Formula: see text]], [Formula: see text]) in the PHQ-9 scale, when evaluating depressive symptoms. In the case of the migraine-related symptoms, we found mean reductions of [Formula: see text] (CI [[Formula: see text]], [Formula: see text]) points in the HIT6 scale, [Formula: see text] (CI [[Formula: see text]], [Formula: see text]) in the MIDAS scale, [Formula: see text] (CI [[Formula: see text]], [Formula: see text]) points in the VAS scale and of [Formula: see text] (CI [[Formula: see text]], [Formula: see text]) migraine episodes per month. Comorbid patients showed slightly better improvements in BDI, HIT6 scores and migraine frequency compared to monomorbid patients. The latter group manifested better results in MIDAS and VAS scores. CONCLUSION: Treatment with onabotulinumtoxinA leads to a significant reduction of disease severity of both chronic migraine and major depressive disorder in patients comorbid with both diseases. Comparative analyses suggest an equivalent strong effect in monomorbid and comorbid patients, with beneficial effects specifically seen for certain migraine features.


Assuntos
Toxinas Botulínicas Tipo A , Transtorno Depressivo Maior , Transtornos de Enxaqueca , Teorema de Bayes , Toxinas Botulínicas Tipo A/uso terapêutico , Doença Crônica , Depressão/complicações , Depressão/tratamento farmacológico , Humanos , Transtornos de Enxaqueca/complicações , Transtornos de Enxaqueca/tratamento farmacológico , Resultado do Tratamento
5.
Behav Brain Funct ; 16(1): 6, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32522229

RESUMO

Glutamatergic AMPA and NMDA receptors in the ventral tegmental area (VTA) are central for cocaine first exposure and posterior craving maintenance. However, the exact rules that coordinate the synaptic dynamics of these receptors in dopaminergic VTA neurons and behavioral outcomes are poorly understood. Additionally, synaptic homeostatic plasticity is present in response to chronic excitability changes in neuronal circuits, adjusting the strength of synapses to stabilize the firing rate. Despite having correspondent mechanisms, little is known about the relationship between continuous cocaine exposure and homeostatic synaptic changes in the VTA neurons. Here, we assess the role of homeostatic mechanisms in the neurobiology of cocaine addiction by providing a brief overview of the parallels between cocaine-induced synaptic potentiation and long-term synaptic adaptations, focusing on the regulation of GluA1- and GluN1- containing receptors.


Assuntos
Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Cocaína/farmacologia , Homeostase/efeitos dos fármacos , Receptores de Glutamato/efeitos dos fármacos , Receptores de Glutamato/metabolismo , Sinapses/efeitos dos fármacos , Animais , Humanos , Potenciação de Longa Duração/efeitos dos fármacos , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Plasticidade Neuronal , Ratos , Receptores de AMPA/biossíntese , Receptores de AMPA/genética , Receptores de N-Metil-D-Aspartato/biossíntese , Receptores de N-Metil-D-Aspartato/genética
6.
Hippocampus ; 29(8): 755-761, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30767318

RESUMO

Prolonged increases in excitation can trigger cell-wide homeostatic responses in neurons, altering membrane channels, promoting morphological changes, and ultimately reducing synaptic weights. However, how synaptic downscaling interacts with classical forms of Hebbian plasticity is still unclear. In this study, we investigated whether chronic optogenetic stimulation of hippocampus CA1 pyramidal neurons in freely moving mice could (a) cause morphological changes reminiscent of homeostatic scaling, (b) modulate synaptic currents that might compensate for chronic excitation, and (c) lead to alterations in Hebbian plasticity. After 24 hr of stimulation with 15-ms blue light pulses every 90 s, dendritic spine density and area were reduced in the CA1 region of mice expressing channelrhodopsin-2 (ChR2) when compared to controls. This protocol also reduced the amplitude of mEPSCs for both the AMPA and NMDA components in ex vivo slices obtained from ChR2-expressing mice immediately after the end of stimulation. Finally, chronic stimulation impaired the induction of LTP and facilitated that of LTD in these slices. Our results indicate that neuronal responses to prolonged network excitation can modulate subsequent Hebbian plasticity in the hippocampus.


Assuntos
Potenciais de Ação/fisiologia , Espinhas Dendríticas/fisiologia , Hipocampo/fisiologia , Plasticidade Neuronal/fisiologia , Animais , Camundongos , Neurônios/fisiologia , Optogenética , Sinapses/fisiologia
7.
Learn Mem ; 22(3): 159-69, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25691516

RESUMO

Memory extinction involves the formation of a new associative memory that inhibits a previously conditioned association. Nonetheless, it could also depend on weakening of the original memory trace if extinction is assumed to have multiple components. The phosphatase calcineurin (CaN) has been described as being involved in extinction but not in the initial consolidation of fear learning. With this in mind, we set to study whether CaN could have different roles in distinct components of extinction. Systemic treatment with the CaN inhibitors cyclosporin A (CsA) or FK-506, as well as i.c.v. administration of CsA, blocked within-session, but not between-session extinction or initial learning of contextual fear conditioning. Similar effects were found in multiple-session extinction of contextual fear conditioning and in auditory fear conditioning, indicating that CaN is involved in different types of short-term extinction. Meanwhile, inhibition of protein synthesis by cycloheximide (CHX) treatment did not affect within-session extinction, but disrupted fear acquisition and slightly impaired between-session extinction. Our results point to a dissociation of within- and between-session extinction of fear conditioning, with the former being more dependent on CaN activity and the latter on protein synthesis. Moreover, the modulation of within-session extinction did not affect between-session extinction, suggesting that these components are at least partially independent.


Assuntos
Calcineurina/fisiologia , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Medo/fisiologia , Animais , Calcineurina/farmacologia , Inibidores de Calcineurina/farmacologia , Condicionamento Clássico/efeitos dos fármacos , Ciclosporina/farmacologia , Extinção Psicológica/efeitos dos fármacos , Medo/efeitos dos fármacos , Infusões Intraventriculares , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Tacrolimo/farmacologia
8.
Biology (Basel) ; 12(4)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37106835

RESUMO

Prepulse inhibition (PPI) is a widely investigated behavior to study the mechanisms of disorders such as anxiety, schizophrenia, and bipolar mania. PPI has been observed across various vertebrate and invertebrate species; however, it has not yet been reported in adult Drosophila melanogaster. In this study, we describe the first detection of PPI of visually evoked locomotor arousal in flies. To validate our findings, we demonstrate that PPI in Drosophila can be partially reverted by the N-methyl D-aspartate (NMDA) receptor antagonist MK-801, known for inducing sensorimotor gating deficits in rodent models. Additionally, we show that the visually evoked response can be inhibited by multiple stimuli presentation, which can also be affected by MK-801. Given the versatility of Drosophila as a model organism for genetic screening and analysis, our results suggest that high-throughput behavioral screenings of adult flies can become a valuable tool for investigating the mechanisms behind PPI.

9.
Biomedicines ; 11(1)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36672700

RESUMO

MK-801, also called dizocilpine, is an N-methyl-D-aspartate (NMDA) receptor antagonist widely used in animal research to model schizophrenia-like phenotypes. Although its effects in rodents are well characterised, little is known about the outcomes of this drug in other organisms. In this study, we characterise the effects of MK-801 on the locomotion, sleep, and negative geotaxis of the fruit fly Drosophila melanogaster. We observed that acute (24 h) and chronic (7 days) administration of MK-801 enhanced negative geotaxis activity in the forced climbing assay for all tested concentrations (0.15 mM, 0.3 mM, and 0.6 mM). Moreover, acute administration, but not chronic, increased the flies' locomotion in a dose-dependent matter. Finally, average sleep duration was not affected by any concentration or administration protocol. Our results indicate that acute MK-801 could be used to model hyperactivity phenotypes in Drosophila melanogaster. Overall, this study provides further evidence that the NMDA receptor system is functionally conserved in flies, suggesting the usefulness of this model to investigate several phenotypes as a complement and replacement of the rodent models within drug discovery.

10.
Neural Regen Res ; 17(1): 20-24, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34100421

RESUMO

Mechanisms of homeostatic plasticity promote compensatory changes of cellular excitability in response to chronic changes in the network activity. This type of plasticity is essential for the maintenance of brain circuits and is involved in the regulation of neural regeneration and the progress of neurodegenerative disorders. One of the most studied homeostatic processes is synaptic scaling, where global synaptic adjustments take place to restore the neuronal firing rate to a physiological range by the modulation of synaptic receptors, neurotransmitters, and morphology. However, despite the comprehensive literature on the electrophysiological properties of homeostatic scaling, less is known about the structural adjustments that occur in the synapses and dendritic tree. In this study, we performed a meta-analysis of articles investigating the effects of chronic network excitation (synaptic downscaling) or inhibition (synaptic upscaling) on the dendritic spine density of neurons. Our results indicate that spine density is consistently reduced after protocols that induce synaptic scaling, independent of the intervention type. Then, we discuss the implication of our findings to the current knowledge on the morphological changes induced by homeostatic plasticity.

11.
Front Nutr ; 9: 889926, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35619965

RESUMO

Meal timing has significant effects on health. However, whether meal timing is associated with the risk of developing and dying of cancer is not well-researched in humans. In the present study, we used data from 941 community-dwelling men aged 71 years who participated in the Uppsala Longitudinal Study of Adult Men to examine the association of meal timing with cancer morbidity and fatal cancer. The following meal timing variables were derived from 7-day food diaries: (i) daily eating duration, i.e., the time between the first and last eating episode of an arbitrary day; (ii) the calorically weighted midpoint of the daily eating interval, a proxy of when the eating window typically occurs during an arbitrary day; and (iii) the day-to-day variability in the timing of eating. We also assessed the reported daily energy intake reliability using the Goldberg method. During a mean observational period of 13.4 years, 277 men (29.4%) were diagnosed with cancer. Furthermore, 191 men (20%) died from cancer during 14.7 years of follow-up. As shown by Cox regression adjusted for potential confounders (e.g., smoking status and daily energy intake), men with reliable dietary reports whose daily eating intervals were on average 13 h long had a 2.3-fold greater fatal cancer risk than men whose daily eating windows were on average about 11 h long. We also found that men with an average day-to-day variability in the timing of eating of 48 to 74 min had a 2- to 2.2-fold higher fatal cancer risk than those with the lowest average day-to-day variability in the timing of eating (i.e., 23 min). No clear associations were found in men with inadequate dietary reports, emphasizing the need to consider the reliability of dietary records in nutritional epidemiology. To fully unlock its potential, studies are needed to test whether recommendations to time-restrict the 24-h eating interval and reduce day-to-day variability in the timing of eating can meaningfully alter the risk of death due to cancer.

12.
Cells ; 11(6)2022 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-35326421

RESUMO

The statin drug target, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), is strongly linked to body mass index (BMI), yet how HMGCR influences BMI is not understood. In mammals, studies of peripheral HMGCR have not clearly identified a role in BMI maintenance and, despite considerable central nervous system expression, a function for central HMGCR has not been determined. Similar to mammals, Hmgcr is highly expressed in the Drosophila melanogaster brain. Therefore, genetic and pharmacological studies were performed to identify how central Hmgcr regulates Drosophila energy metabolism and feeding behavior. We found that inhibiting Hmgcr, in insulin-producing cells of the Drosophila pars intercerebralis (PI), the fly hypothalamic equivalent, significantly reduces the expression of insulin-like peptides, severely decreasing insulin signaling. In fact, reducing Hmgcr expression throughout development causes decreased body size, increased lipid storage, hyperglycemia, and hyperphagia. Furthermore, the Hmgcr induced hyperphagia phenotype requires a conserved insulin-regulated α-glucosidase, target of brain insulin (tobi). In rats and mice, acute inhibition of hypothalamic Hmgcr activity stimulates food intake. This study presents evidence of how central Hmgcr regulation of metabolism and food intake could influence BMI.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Animais , Drosophila melanogaster/metabolismo , Ingestão de Alimentos , Metabolismo Energético , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Hiperfagia , Insulina/metabolismo , Mamíferos/metabolismo , Camundongos , Ratos
13.
Cells ; 11(22)2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36428957

RESUMO

The underlying mechanisms for statin-induced myopathy (SIM) are still equivocal. In this study, we employ Drosophila melanogaster to dissect possible underlying mechanisms for SIM. We observe that chronic fluvastatin treatment causes reduced general locomotion activity and climbing ability. In addition, transmission microscopy of dissected skeletal muscles of fluvastatin-treated flies reveals strong myofibrillar damage, including increased sarcomere lengths and Z-line streaming, which are reminiscent of myopathy, along with fragmented mitochondria of larger sizes, most of which are round-like shapes. Furthermore, chronic fluvastatin treatment is associated with impaired lipid metabolism and insulin signalling. Mechanistically, knockdown of the statin-target Hmgcr in the skeletal muscles recapitulates fluvastatin-induced mitochondrial phenotypes and lowered general locomotion activity; however, it was not sufficient to alter sarcomere length or elicit myofibrillar damage compared to controls or fluvastatin treatment. Moreover, we found that fluvastatin treatment was associated with reduced expression of the skeletal muscle chloride channel, ClC-a (Drosophila homolog of CLCN1), while selective knockdown of skeletal muscle ClC-a also recapitulated fluvastatin-induced myofibril damage and increased sarcomere lengths. Surprisingly, exercising fluvastatin-treated flies restored ClC-a expression and normalized sarcomere lengths, suggesting that fluvastatin-induced myofibrillar phenotypes could be linked to lowered ClC-a expression. Taken together, these results may indicate the potential role of ClC-a inhibition in statin-associated muscular phenotypes. This study underlines the importance of Drosophila melanogaster as a powerful model system for elucidating the locomotion and muscular phenotypes, promoting a better understanding of the molecular mechanisms underlying SIM.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Doenças Musculares , Animais , Humanos , Drosophila melanogaster/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Canais de Cloreto/metabolismo , Fluvastatina/efeitos adversos , Doenças Musculares/genética , Drosophila/metabolismo , Locomoção , Fenótipo
14.
Methods Mol Biol ; 2191: 391-401, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32865756

RESUMO

In vivo optogenetic strategies have been fundamental for the investigation of how neural circuits relate to behavior. While short-term experimental procedures are typically used in such studies, chronic stimulation during behavioral sessions has been largely unexplored. Here we describe a protocol for long-term optogenetic modulation of neuronal populations in freely moving animals.


Assuntos
Encéfalo/metabolismo , Neurônios/metabolismo , Optogenética/métodos , Animais , Encéfalo/patologia , Neurônios/patologia , Roedores
15.
J Neuroimmunol ; 358: 577658, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34304141

RESUMO

Several neurological symptoms and complications have been described in association with COVID-19, such as anosmia, ageusia, encephalitis and Guillain-Barré syndrome. Here, we review the literature describing SARS-CoV-2-induced neurological manifestations and provide a comprehensive discussion of proposed mechanisms underlying the neurological pathophysiology. First, we analyse the neuroinvasiveness potential of the coronavirus family based on previous SARS-CoV-1 studies. Then, we describe the current evidence on COVID-19-induced nervous tissue damage, including processes behind brain vasculopathy and cytokine storm. We also discuss in detail anosmia and Guillain-Barré syndrome. Finally, we provide a summarised timeline of the main findings in the field. Future perspectives are presented, and suggestions of further investigations to clarify how SARS-COV-2 can affect the CNS.


Assuntos
Encéfalo/imunologia , COVID-19/complicações , COVID-19/imunologia , Doenças do Sistema Nervoso/etiologia , Doenças do Sistema Nervoso/imunologia , SARS-CoV-2/imunologia , Animais , Encéfalo/patologia , COVID-19/diagnóstico , Humanos , Doenças do Sistema Nervoso/diagnóstico
16.
Endocrine ; 71(1): 3-8, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33179220

RESUMO

PURPOSE: Throughout the SARS-CoV2 pandemic, multiple reports show higher percentages of hospitalization, morbidity, and mortality among men than women, indicating that men are more affected by COVID-19. The pathophysiology of this difference is yet not established, but recent studies suggest that sex hormones may influence the viral infectivity process. Here, we review the current evidence of androgen sensitivity as a decisive factor for COVID-19 disease severity. METHODS: Relevant literature investigating the role of androgens in COVID-19 was assessed. Further, we describe several drugs suggested as beneficial for COVID-19 treatment related to androgen pathways. Lastly, we looked at androgen sensitivity as a predictor for COVID-19 progression and ongoing clinical trials on androgen suppression therapies as a line of treatment. RESULTS: SARS-COV2 virus spike proteins utilize Transmembrane protease serine 2 (TMPRSS2) for host entry. Androgen receptors are transcription promoters for TMPRSS2 and can, therefore, facilitate SARS-COV2 entry. Variants in the androgen receptor gene correlate with androgen sensitivity and are implicated in diseases like androgenetic alopecia and prostate cancer, conditions that have been associated with worse COVID-19 outcomes and hospitalization. CONCLUSION: Androgen's TMPRSS2-mediated actions might explain both the low fatalities observed in prepubertal children and the differences between sexes regarding SARS-COV2 infection. Androgen sensitivity may be a critical factor in determining COVID-19 disease severity, and sensitivity tests can, therefore, help in predicting patient outcomes.


Assuntos
Androgênios/fisiologia , COVID-19/epidemiologia , COVID-19/patologia , Caracteres Sexuais , Adulto , Criança , Progressão da Doença , Feminino , Humanos , Masculino , Pandemias , SARS-CoV-2/fisiologia , Serina Endopeptidases/fisiologia , Índice de Gravidade de Doença , Internalização do Vírus
17.
Front Neurosci ; 15: 653470, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34079435

RESUMO

More than 320 million people live with depression in the world, a disorder that severely limits psychosocial functioning and diminishes quality of life. The prevalence of major depression is almost two times higher in women than in men. However, the molecular mechanisms of its sex-specific pathophysiology are still poorly understood. Drosophila melanogaster is an established model for neurobiological research of depression-like states, as well as for the study of molecular and genetic sex differences in the brain. Here, we investigated sex-specific effects on forced-climbing locomotion (negative geotaxis) and gene expression of a fly model of depression-like phenotypes induced by levodopa administration, which was previously shown to impair normal food intake, mating frequency, and serotonin concentration. We observed that both males and females show deficits in the forced-climbing paradigm; however, modulated by distinct gene expression patterns after levodopa administration. Our results suggest that Drosophila models can be a valuable tool for identifying the molecular mechanisms underlying the difference of depressive disorder prevalence between men and women.

18.
Neurosci Biobehav Rev ; 120: 1-12, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33242563

RESUMO

The assessment of behavioral outcomes is a central component of neuroscientific research, which has required continuous technological innovations to produce more detailed and reliable findings. In this article, we provide an in-depth review on the progress and future implications for three model organisms (mouse, rat, and Drosophila) essential to our current understanding of behavior. By compiling a comprehensive catalog of popular assays, we are able to compare the diversity of tasks and usage of these animal models in behavioral research. This compilation also allows for the evaluation of existing state-of-the-art methods and experimental applications, including optogenetics, machine learning, and high-throughput behavioral assays. We go on to discuss novel apparatuses and inter-species analyses for centrophobism, feeding behavior, aggression and mating paradigms, with the goal of providing a unique view on comparative behavioral research. The challenges and recent advances are evaluated in terms of their translational value, ethical procedures, and trustworthiness for behavioral research.


Assuntos
Neurociências , Roedores , Agressão , Animais , Pesquisa Comportamental , Camundongos , Modelos Animais , Ratos
19.
Res Synth Methods ; 11(5): 655-668, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32583923

RESUMO

Meta-analytic methods are powerful resources to summarize the existing evidence concerning a given research question and are widely used in many academic fields. Meta-analyzes can also be used to study sources of heterogeneity and bias among results, which should be considered to avoid inaccuracies. Many of these sources can be related to study authorship, as both methodological heterogeneity and researcher bias may lead to deviations in results between different research groups. In this work, we describe a method to objectively attribute study authorship within a given meta-analysis to different research groups by using graph cluster analysis of collaboration networks. We then provide empirical examples of how the research group of origin can impact effect size in distinct types of meta-analyzes, demonstrating how non-independence between within-group results can bias effect size estimates if uncorrected. Finally, we show that multilevel random-effects models using research group as a level of analysis can be a simple tool for correcting for authorship dependence in results.


Assuntos
Metanálise como Assunto , Publicações , Algoritmos , Viés , Análise por Conglomerados , Dessensibilização e Reprocessamento através dos Movimentos Oculares , Humanos , Linguagens de Programação , Reprodutibilidade dos Testes , Projetos de Pesquisa , Tamanho da Amostra , Software , Transtornos de Estresse Pós-Traumáticos/terapia
20.
Artigo em Inglês | MEDLINE | ID: mdl-32116619

RESUMO

Optogenetics is revolutionizing Neuroscience, but an often neglected effect of light stimulation of the brain is the generation of heat. In extreme cases, light-generated heat kills neurons, but mild temperature changes alter neuronal function. To date, most in vivo experiments rely on light stimulation of neural tissue using fiber-coupled lasers of various wavelengths. Brain tissue is irradiated with high light power that can be deleterious to neuronal function. Furthermore, absorbed light generates heat that can lead to permanent tissue damage and affect neuronal excitability. Thus, light alone can generate effects in neuronal function that are unrelated to the genuine "optogenetic effect." In this work, we perform a theoretical analysis to investigate the effects of heat transfer in rodent brain tissue for standard optogenetic protocols. More precisely, we first use the Kubelka-Munk model for light propagation in brain tissue to observe the absorption phenomenon. Then, we model the optothermal effect considering the common laser wavelengths (473 and 593 nm) used in optogenetic experiments approaching the time/space numerical solution of Pennes' bio-heat equation with the Finite Element Method. Finally, we then modeled channelrhodopsin-2 in a single and spontaneous-firing neuron to explore the effect of heat in light stimulated neurons. We found that, at commonly used light intensities, laser radiation considerably increases the temperature in the surrounding tissue. This effect alters action potential size and shape and causes an increase in spontaneous firing frequency in a neuron model. However, the shortening of activation time constants generated by heat in the single firing neuron model produces action potential failures in response to light stimulation. We also found changes in the power spectrum density and a reduction in the time required for synchronization in an interneuron network model of gamma oscillations. Our findings indicate that light stimulation with intensities used in optogenetic experiments may affect neuronal function not only by direct excitation of light sensitive ion channels and/or pumps but also by generating heat. This approach serves as a guide to design optogenetic experiments that minimize the role of tissue heating in the experimental outcome.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA