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 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
Deep brain stimulation (DBS) appeared in the therapeutic framework for Parkinson's disease in the late 1980 s and early 1990 s, conceived as an alternative to ablative treatments, using inhibitory electrical stimulation parameters still clinically in force today, with frequencies above 130 Hz, a pulse width of 60 ms and current intensity around 3 mA into deep brain structures, to relieve the motor symptoms of the disease. This context expands into a technique not only restricted to the targets traditionally used in lesional procedures, supported by the knowledge acquired with non-human primate (NHP) animal models during the early 1990 s, initiated by Benazzouz and collaborators. Currently, NHP animal models have lost ground to research models in rodents, which have assumed a prominent position in scientific research on DBS. However, how can an animal so small and different from Homo sapiens provide relevant information that may guide the evolution of treatment for a condition that occurs only in humans, like PD? The scope of this review is to address recent advances in PD pathogeny, DBS principles, and different in vivo experimental DBS models in rodents, their limitations and relevance, as well as the future directions in animal models for scientific research.
Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson , Animais , Encéfalo , Estimulação Encefálica Profunda/métodos , Humanos , Doença de Parkinson/terapia , Primatas , RoedoresRESUMO
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.