Neurological function is restored post-ischemic stroke in zebrafish, with aging exerting a deleterious effect on its pathology

Abstract

Ischemic stroke (IS) is a pathological condition characterized by the cessation of blood flow due to factors such as thrombosis, inflicting severe damage to the cranial nervous system and resulting in numerous disabilities including memory impairments and hemiplegia. Despite the critical nature of this condition, therapeutic options remain limited, with a pressing challenge being the development of treatments aimed at restoring neurological function. In this study, we leveraged zebrafish, renowned for their exceptional regenerative capabilities, to analyze the pathology of IS and the subsequent recovery process. We induced photothrombosis in the telencephalon utilizing rose bengal and conducted a temporal investigation of changes in cerebral vascular function and learning ability. Our findings revealed that blood flow in young zebrafish was restored approximately 7 days post-IS induction (dpi), with brain function recuperating by 14 dpi. Furthermore, we observed an escalation in the expression of the neural stem marker gene at 3dpi, followed by an upregulation of the differentiated neuron marker at 7 and 14dpi. In the aged IS model, symptoms were exacerbated. While cerebral blood flow was restored in 7 days, similar to young zebrafish, the recovery of learning ability was protracted in aged fish. Moreover, an upregulation of the differentiated neuron marker seen in young fish was not observed in the aged model. Collectively, our analysis of the zebrafish IS model and its comparison with existing rodent models may lay the groundwork for novel IS treatment strategies. Furthermore, the zebrafish IS model may prove beneficial for analyzing the impact of aging on the pathology of IS and the recovery process.