http://hdl.handle.net/10183/19212 2026-11-14T10:15:58Z http://hdl.handle.net/10183/308886 Espécies medicinais comercializadas como "quebra -pedras em Porto Alegre, Rio Grande do Sul, Brasil Aita, Adriana Morais; Matsuura, Hélio Nitta; Machado, Clarice Azevedo; Ritter, Mara Rejane 2009-01-01T00:00:00Z http://hdl.handle.net/10183/308856 Unpredictable chronic stress fails to induce robust changes in zebrafish social behavior Neves, Náthali Ávila; Lopes, Matheus Gallas; Alves, Amanda Patelli; Müller, Daniela Varisco; Bastos, Leonardo Marensi; Buss, Thailana Stahlhofer; Herrmann, Ana Paula; Piato, Angelo Luis Stapassoli Stress-related disorders encompass diverse behavioral alterations, including impaired social functioning. The zebrafish (Danio rerio) is a valuable model for studying these phenomena, particularly because of its robust and ethologically conserved social behaviors. Unpredictable chronic stress (UCS) produces behavioral, physiological, and molecular changes in zebrafish that parallel core features of human anxiety and depressive disorders; however, its impact on social outcomes remains unclear. Here, we examined whether a 14-day UCS protocol alters social behavior in adult zebrafish using two complementary assays: the social preference test and the shoal cohesion test. Across two independent experiments, UCS did not elicit detectable changes in individual social approach or group-level cohesion. In contrast, UCS induced clear anxiety-like behavior in the novel tank test, validating the stress manipulation, with stressed fish displaying reduced vertical exploration and decreased time in the upper zone. Distance-based shoal dispersion measures increased over time in both groups, indicating reduced shoal cohesion, consistent with habituation to the testing environment rather than a stress-specific effect. Together, these results suggest that social behavior in adult zebrafish is relatively resilient to UCS under the conditions tested, whereas anxiety-like responses are markedly affected. Future work should investigate whether factors such as stressor intensity, developmental stage, sex composition, or social hierarchy modulate the sensitivity of social behavior to chronic stress. 2026-01-01T00:00:00Z http://hdl.handle.net/10183/308838 Modifiable risk factors associated with the risk of developing Parkinson’s disease : a critical review Tumas, Vitor; Schuh, Artur Francisco Schumacher; Mata, Ignacio Fernandez The etiology of Parkinson’s disease (PD) is complex and multifactorial, depending on interactions involving environmental/lifestyle and genetic factors. The genetic aspects of the disease are becoming well characterized, while the environmental factors still need further investigation. In the present narrative review, we have described the most concrete evidence of associations between environmental factors and the risk of developing PD. Physical activity, healthy dietary patterns, smoking, and caffeine intake are protective factors against PD. Head trauma, consumption of milk and dairy products, and pesticide exposure were associated with a higher risk of developing PD. The associations of alcohol consumption, living in rural areas, farming, and consumption of well water with PD are still controversial. Results of several studies strongly suggest that diabetes mellitus is a risk factor for the development of PD, as well as the pre-diabetic state. Lower serum levels of uric acid were associated with an increased risk of developing PD and with worse clinical features and faster progression of symptoms. The protective effects of nonsteroidal antiinflammatory drugs use are controversial. Several other factors were potentially associated with the risk of developing PD: environmental pollutants such as organic solvents, exposure to sunlight, vitamin D deficiency, bullous pemphigoid, bipolar disorder, inflammatory bowel disease, irritable bowel syndrome, certain infections and agents, and essential tremor. Environmental factors are important risk markers for the development of PD. Understanding these risks and protective factors could lead to the implementation of risk-modifying actions for PD. 2025-01-01T00:00:00Z http://hdl.handle.net/10183/308829 Hyposmia in Parkinson’s disease : exploring selective odour loss Mitchell, Eleanor; Oliveira, Christian Mattjie de; Bestwick, Jonathan Paul; Barros, Rodrigo Coelho; Schuh, Artur Francisco Schumacher; Simonet, Cristina; Noyce, Alastair John Smell loss is a frequent and early manifestation of Parkinson’s disease (PD), serving as a sensitive - albeit nonspecific - clinical biomarker1. The notion that PD causes odour-selective hyposmia has been debated for three decades. Previous studies have used healthy controls as the comparator; this is problematic given the majority presumably display normal olfactory function. Using University of Pennsylvania Smell Identification Test data from the Parkinson’s Progression Markers Initiative, we trained eight machine learning models to distinguish ‘PD hyposmia’ (n = 155) from ‘non-PD hyposmia’ (n = 155). The best-performing models were evaluated on an independent validation cohort. While specific responses (e.g. mistaking pizza for bubble gum) were impactful across models, at best only 63% of PD cases were correctly identified. Given we used a balanced data set, 50% accuracy would be achieved by random guessing. This suggests that PD-related hyposmia does not exhibit a unique pattern of odour selectivity distinct from general hyposmia. 2025-01-01T00:00:00Z