Olfactory Dysfunction in a Novel Model of Prodromal Parkinson’s Disease in Adult Zebrafish

Document Type

Article

Publication Date

5-1-2025

Publication Source

International Journal of Molecular Sciences

Volume Number

26

Issue Number

10

ISSN

16616596

E-ISSN

14220067

Article Number

4474

Abstract

Olfactory dysfunction is a clinical marker of prodromal Parkinson’s disease (PD), yet the underlying mechanisms remain unclear. To explore this relationship, we developed a zebrafish model that recapitulates the olfactory impairment observed in prodromal PD without affecting motor function. We used zebrafish due to their olfactory system’s similarity to mammals and their unique nervous system regenerative capacity. By injecting 6-hydroxydopamine (6-OHDA) into the dorsal telencephalic ventricle, we observed a significant loss of dopaminergic (DA) periglomerular neurons in the olfactory bulb (OB) and retrograde degeneration of olfactory sensory neurons (OSNs) in the olfactory epithelium (OE). These alterations impaired olfactory responses to cadaverine, an aversive odorant, while responses to alanine remained intact. 6-OHDA also triggered robust neuroinflammatory responses. By 7 days post-injection, dopaminergic synapses in the OB were remodeled, OSNs in the OE appeared recovered, and neuroinflammation subsided, leading to full recovery of olfactory responses to cadaverine. These findings highlight the remarkable neuroplasticity of zebrafish and suggest that this model of olfactory dysfunction associated with dopaminergic loss could provide valuable insights into some features of early PD pathology. Understanding the interplay between dopaminergic loss and olfactory dysfunction in a highly regenerative vertebrate may inform therapeutic strategies for individuals suffering from olfactory loss.

Keywords

dopaminergic loss, neurogenesis, neuroinflammation, olfactory dysfunction, olfactory system, Parkinson’s disease, zebrafish

Link to Full Text

Share

COinS