Quantification of Main Olfactory Epithelium Thickness in Mice With Impaired Olfactory Function

• Thomas Ring, Neuroscience, University of Delaware

• Joshua Neunuebel, Psychological and Brain Sciences, University of Delaware

Olfaction is essential for social, reproductive, and health-related behaviors in animals (Ryan et al., 2008). Chemically induced olfactory dysfunction using agents such as Methimazole (MMZ) and Triton X‑100 is a standard approach to study the mammalian main olfactory epithelium (MOE) (Lakshmanan et al., 2022). While behavioral deficits from these treatments have been demonstrated using the buried food test (Zhao et al., 2025; Huang et al., 2022), a quantitative histological assessment of MOE damage has not been fully explored. To address this, we quantified MOE thickness following treatment with 0.7% Triton X-100 (n = 11) or saline (n = 8), or injection with 100 mg/kg MMZ (n = 8) or saline (n = 8). Tissues were decalcified, cryoprotected, sectioned, and stained with cresyl violet before measuring the thickness of MOE in ImageJ. Both MMZ and Triton X-100 significantly reduced MOE thickness (MMZ: t = −4.85, df = 10.094, p < 0.001, Cohen’s d = −2.42, Welch’s two-sample t-test; Triton X-100: t = −2.93, df = 16.886, p < 0.01, Cohen’s d = −1.27, Welch’s two-sample t-test). These findings validate MMZ and Triton X-100 as effective models for diminishing anatomical olfactory tissue and provide a foundation for future studies on sensory-guided social behaviors.