Structural regeneration and functional recovery of the olfactory system of zebrafish following brain injury

Abstract

Olfactory dysfunction is a common outcome of brain injuries, negatively affecting quality of life. The mammalian nervous system has limited capacity for spontaneous olfactory recovery, making it challenging to study olfactory regeneration and recovery in adults. In contrast, zebrafish are an ideal model for such studies due to its extensive and lifelong regenerative abilities. In this work, we describe a model of excitotoxic injury in the olfactory bulb using quinolinic acid (QA) lesions in adult zebrafish. We observed extensive neurodegeneration in both the olfactory bulb and olfactory epithelium, including a reduction of bulbar volume, neuronal death, and impaired olfactory function. Recovery mechanisms involved tissue remodeling, cell proliferation, neurogenesis, leading to full restoration of olfactory function by 21 days. This study provides a model to further investigate the effects of excitotoxicity on olfactory dysfunction, and highlights zebrafishs remarkable regenerative abilities, providing insights into potential therapeutic strategies for restoring olfactory function following brain injuries.