RESUMO
Levodopa (L-DOPA) is the classical gold standard treatment for Parkinson's disease. However, its chronic administration can lead to the development of L-DOPA-induced dyskinesias (LIDs). Dysregulation of the nitric oxide-cyclic guanosine monophosphate pathway in striatal networks has been linked to deficits in corticostriatal transmission in LIDs. This study investigated the effects of the nitric oxide (NO) donor sodium nitroprusside (SNP) on behavioural and electrophysiological outcomes in sham-operated and 6-hydroxydopamine-lesioned rats chronically treated with vehicle or L-DOPA, respectively. In sham-operated animals, systemic administration of SNP increased the spike probability of putative striatal medium spiny neurons (MSNs) in response to electrical stimulation of the primary motor cortex. In 6-hydroxydopamine-lesioned animals, SNP improved the stepping test performance without exacerbating abnormal involuntary movements. Additionally, SNP significantly increased the responsiveness of putative striatal MSNs in the dyskinetic striatum. These findings highlight the critical role of the NO signalling pathway in facilitating the responsiveness of striatal MSNs in both the intact and dyskinetic striata. The study suggests that SNP has the potential to enhance L-DOPA's effects in the stepping test without exacerbating abnormal involuntary movements, thereby offering new possibilities for optimizing Parkinson's disease therapy. In conclusion, this study highlights the involvement of the NO signalling pathway in the pathophysiology of LIDs.
Assuntos
Discinesias , Doença de Parkinson , Ratos , Animais , Levodopa/efeitos adversos , Nitroprussiato/farmacologia , Oxidopamina/toxicidade , Neurônios Espinhosos Médios , Óxido Nítrico/metabolismo , Discinesias/metabolismo , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Antiparkinsonianos/efeitos adversosRESUMO
This study aimed to explore the impact of anxiety and functional impairment measures on a sample of undergraduate psychology students. Learning performance was evaluated during the emergency remote teaching during the first wave and in the post-vaccination period of the COVID-19 pandemic in Brazil. Data modeling revealed that psychometric indicators of severe anxiety and severe functional impairment predicted students with lower learning performance in pairs of pre- and post-test multiple-choice questions. This is the first study to highlight the association between measures of generalized anxiety and functional impairment having a deleterious impact on students' learning performance. This manuscript highlights that educational policies should be designed to deal with students' mental health under stressful situations.
Assuntos
COVID-19 , Pandemias , Humanos , COVID-19/epidemiologia , Ansiedade , Transtornos de Ansiedade , EstudantesRESUMO
This study examined the psychometric properties of a Brazilian adapted version of the Coronavirus Anxiety Scale (CAS-BR) in a sample of adults in Brazil. Confirmatory factor analyses demonstrated that the CAS-BR produces a reliable (α = .84), unidimensional construct whose structure was shown to be invariant across gender, race, and age. However, some items of the CAS-BR were stronger indicators of the coronavirus anxiety construct for women and younger adults. Although the CAS-BR demonstrated evidence of discrimination ability for functional impairment (AUC = .77), Youden indexes were low to identify a clinical cut-score. Construct validity was demonstrated with correlations between CAS-BR scores and measures of functional impairment, generalized anxiety, and depression. Exploratory analyses revealed that CAS-BR total scores were higher among women and participants with a history of anxiety disorder. These findings are consistent with previous investigations and support the validity of CAS-BR for measuring coronavirus anxiety with Brazilian adults.
Assuntos
Coronavirus , Adulto , Humanos , Feminino , Brasil , Psicometria , Ansiedade/diagnóstico , Transtornos de Ansiedade/diagnóstico , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosRESUMO
The facilitation of corticostriatal transmission is modulated by the pharmacological inhibition of striatal phosphodiesterase 10A (PDE10A). Since L-DOPA-induced dyskinesia is associated with abnormal corticostriatal transmission, we hypothesized that inhibition of PDE10A would modulate L-DOPA-induced dyskinesia (LID) by regulating corticostriatal activity. 6-OHDA-lesioned rats were chronically treated with L-DOPA for one week. After that, for two additional weeks, animals were treated with the PDE10A inhibitor PDM-042 (1 and 3 mg/kg) one hour before L-DOPA. Behavioral analyses were performed to quantify abnormal involuntary movements (AIMs) and to assess the antiparkinsonian effects of L-DOPA. Single-unit extracellular electrophysiological recordings were performed in vivo to characterize the responsiveness of MSNs to cortical stimulation. The low dose of PDM-042 had an antidyskinetic effect (i.e., attenuated peak-dose dyskinesia) and did not interfere with cortically evoked spike activity. Conversely, the high dose of PDM-042 did not affect peak-dose dyskinesia, prolonged AIMs, and increased cortically evoked spike activity. These data suggest that the facilitation of corticostriatal transmission is likely to contribute to the expression of AIMs. Therefore, cyclic nucleotide manipulation is an essential target in controlling LID.
Assuntos
Antiparkinsonianos/uso terapêutico , Levodopa/uso terapêutico , Oxidopamina , Doença de Parkinson Secundária/tratamento farmacológico , Doença de Parkinson Secundária/fisiopatologia , Inibição Pré-Pulso/efeitos dos fármacos , Animais , Antiparkinsonianos/efeitos adversos , Gânglios da Base/efeitos dos fármacos , Gânglios da Base/patologia , Gânglios da Base/fisiopatologia , Modelos Animais de Doenças , Humanos , Levodopa/efeitos adversos , Masculino , Camundongos , Doença de Parkinson Secundária/patologia , Ratos , Ratos WistarRESUMO
L-3,4-Dihydroxyphenylalanine (L-DOPA) remains the most effective symptomatic treatment of Parkinson's disease (PD). However, the long-term use of L-DOPA causes, in combination with disease progression, the development of motor complications termed L-DOPA-induced dyskinesia (LID). LID is the result of profound modifications in the functional organization of the basal ganglia circuitry. There is increasing evidence of the involvement of non-dopaminergic systems on the pathophysiology of LID. This raises the possibility of novel promising therapeutic approaches in the future, including agents that interfere with glutamatergic, serotonergic, adenosine, adrenergic, and cholinergic neurotransmission that are currently in preclinical testing or clinical development. Herein, we summarize the current knowledge of the pharmacology of LID in PD. More importantly, this review attempts to highlight the role of nitric oxide (NO) in PD and provide a comprehensive picture of recent preclinical findings from our group and others showing its potential involvement in dyskinesia.
Assuntos
Antiparkinsonianos/efeitos adversos , Discinesia Induzida por Medicamentos/etiologia , Levodopa/efeitos adversos , Óxido Nítrico/metabolismo , Doença de Parkinson/tratamento farmacológico , Animais , Corpo Estriado/metabolismo , Discinesia Induzida por Medicamentos/tratamento farmacológico , Discinesia Induzida por Medicamentos/metabolismo , Humanos , Doença de Parkinson/metabolismoRESUMO
l-3, 4-dihydroxyphenylalanine (L-DOPA) is the most effective treatment for Parkinson's disease but can induce debilitating abnormal involuntary movements (dyskinesia). Here we show that the development of L-DOPA-induced dyskinesia in the rat is accompanied by upregulation of an inflammatory cascade involving nitric oxide. Male Wistar rats sustained unilateral injections of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle. After three weeks animals started to receive daily treatment with L-DOPA (30 mg/kg plus benserazide 7.5 mg/kg, for 21 days), combined with an inhibitor of neuronal NOS (7-nitroindazole, 7-NI, 30 mg/kg/day) or vehicle (saline-PEG 50%). All animals treated with L-DOPA and vehicle developed abnormal involuntary movements, and this effect was prevented by 7-NI. L-DOPA-treated dyskinetic animals exhibited an increased striatal and pallidal expression of glial fibrillary acidic protein (GFAP) in reactive astrocytes, an increased number of CD11b-positive microglial cells with activated morphology, and the rise of cells positive for inducible nitric oxide-synthase immunoreactivity (iNOS). All these indexes of glial activation were prevented by 7-NI co-administration. These findings provide evidence that the development of L-DOPA-induced dyskinesia in the rat is associated with activation of glial cells that promote inflammatory responses. The dramatic effect of 7-NI in preventing this glial response points to an involvement of nitric oxide. Moreover, the results suggest that the NOS inhibitor prevents dyskinesia at least in part via inhibition of glial cell activation and iNOS expression. Our observations indicate nitric oxide synthase inhibitors as a therapeutic strategy for preventing neuroinflammatory and glial components of dyskinesia pathogenesis in Parkinson's disease.
Assuntos
Antiparkinsonianos/efeitos adversos , Discinesia Induzida por Medicamentos/tratamento farmacológico , Discinesia Induzida por Medicamentos/metabolismo , Indazóis/farmacologia , Levodopa/efeitos adversos , Neuroglia/metabolismo , Fármacos Neuroprotetores/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico/metabolismo , Doença de Parkinson/tratamento farmacológico , Animais , Modelos Animais de Doenças , Inflamação/induzido quimicamente , Levodopa/administração & dosagem , Masculino , Ratos , Ratos Wistar , Regulação para CimaRESUMO
No sistema nervoso, a sinapse é a estrutura que permite a um neurônio passar um sinal elétrico ou químico a outro neurônio ou outra célula (muscular ou glandular). A palavra sinapse vem de "synaptein", palavra que Sir Charles Scott Sherrington e seus colegas acunharam do grego "syn" (junto) e "haptein"(afivelar). As sinapses podem ser separadas entre elétricas e químicas, porém a maior parte da transmissão sináptica é realizada através das sinapses químicas. Apesar das sinapses químicas terem uma resposta mais lenta que as elétricas, elas possuem a vantagem da amplificação do sinal gerada através de uma cascata de segundos mensageiros. As sinapses químicas podem ser excitatórias ou inibitórias e são caracterizadas por um terminal pré-sináptico (onde estão presentes as vesículas que contêm os neurotransmissores) em contato com um terminal pós-sináptico (onde estão presentes os receptores ionotrópicos e metabotrópicos para esses neurotransmissores) separados pela fenda sináptica. As sinapses típicas acontecem sobre axônios (axo-axônicas), sobre dendritos (axo-dendríticas), sobre o soma de outro neurônio (axo-somáticas) e sobre os espinhos dendríticos...
In the nervous system, the synapse is the structure that allows a neuron pass an electrical or chemical signal to another neuron or another cell (muscle or glandular). The word synapse comes from "synaptein" that Sir Charles Scott Sherrington and his colleagues minted from the Greek "syn" (together) and "haptein"(buckling). Most part of the synaptic transmission is performed through chemical synapses. Chemical synapses have a slower response than the electric ones; they have the advantage of amplifying the signal generated through a cascade of second messengers. Chemical synapses can be excitatory or inhibitory and are characterized by a presynaptic terminal (where there are vesicles that contain the neurotransmitters) in contact with a postsynaptic terminal (where there are the ionotropic and metabotropic receptors) separated by the synaptic cleft. Synapses can occur on axons (axo-axonal), on dendrites (axodendritic), on soma (axo-somatic) and on dendritic spines...
Assuntos
Receptores de Neurotransmissores , Transmissão SinápticaRESUMO
A comunicação entre neurônios é passível de constantes modificações, até mesmo no encéfalo adulto. Esta capacidade de circuitos neuronais fortalecerem ou enfraquecerem suas interações sinápticas específicas (fenômeno conhecido como plasticidade sináptica) pode ocorrer de acordo com as diferentes demandas ambientais, o que favorece a noção de que alterações dinâmicas na comunicação entre neurônios estão na base da flexibilidade comportamental (i.e., processos de aprendizagem e memória). Nas últimas décadas, o avanço das neurociências tem permitido uma melhor compreensão a respeito da plasticidade sináptica, especialmente a plasticidade de sinapses glutamatérgicas, cujos processos moleculares de modificação sináptica parecem estar entre os mais comuns de todo o sistema desse progresso na ciência básica tem contribuído para uma melhor compreensão acerca dos processos patológicos envolvendo as sinapses glutamatérgicas, como a doença de Alzheimer. Além disso, a crescente compreensão sobre o funcionamento da comunicação glutamatérgica tem ajudado a esclarecer como as sinapses, em geral, teriam se originado e evoluído na escala filogenética do reino animal (Metazoa)...
Communication between neurons is subject to constant changes, even in the adult brain. This ability of neural circuits to strengthen or weaken their specific synaptic interactions (a phenomenon known assynaptic plasticity) may occur according to different environmental demands, which favors the idea that dynamic changes in the communication between neurons underlie behavioral flexibility (i.e., learning and memory processes). In recent decades, advances in neuroscience has allowed a better understanding of synaptic plasticity, specially the plasticity of glutamatergic synapses, whose molecular processes of synaptic change appear to be among the most common throughout the central nervous system.Much of this progress in basic science has contributed to a better understanding of pathological processes involving the glutamatergic synapses, such as Alzheimer's disease. Furthermore, the growing understanding about the physiology of glutamatergic communication has helped explain how synapses, in general, would have originated and evolved in the phylogenetic scale of the Metazoa...