Therapeutic Effects and Mechanisms of Olfactory Training in a Murine Model of Olfactory Dysfunction

OBJECTIVE: To evaluate the therapeutic effects and mechanisms of olfactory training in a mouse model of olfactory dysfunction. STUDY DESIGN: Randomized controlled animal study. SETTING: Laboratory investigation. METHODS: Thirty BALB/c mice were randomized into control, model, and olfactory training groups. Olfactory dysfunction was induced in the latter 2 groups via 3-methylindole injection. The training group was exposed to 4 distinct odors twice daily for 28 days. Olfactory function was assessed using a buried food pellet test. Olfactory mucosa and bulb tissues were analyzed histologically and for inflammatory markers. RESULTS: Compared to the training group, the model group exhibited significantly prolonged foraging latency, increased levels of inflammatory cytokines (IFN-γ, IL-6, TNF-α) in the olfactory bulb, and reduced olfactory marker protein (OMP) expression. Histology showed mucosal damage in model mice. Olfactory training significantly shortened foraging latency, lowered cytokine levels, increased OMP expression, and improved mucosal pathology. Apoptosis did not differ significantly between groups. CONCLUSION: Olfactory training improved olfactory function in mice, potentially through mechanisms involving reduced olfactory bulb inflammation, promotion of olfactory neuron regeneration, and amelioration of olfactory mucosal damage.