# Relationship Between Nasal Trigeminal Receptor Expression and Trigeminal Sensitivity

## TL;DR

This study explores how nasal trigeminal sensitivity relates to the expression of TRP channels in healthy individuals.

## Contribution

The study identifies a novel link between TRPA1 mRNA expression and trigeminal sensitivity in nasal mucosa.

## Key findings

- Lower lateralization scores correlate with reduced TRPA1 mRNA expression.
- TRPA1 expression may influence behavioral responses to trigeminal stimulation.
- Nasal swabs could serve as a non-invasive tool for assessing trigeminal function.

## Abstract

An intact intranasal trigeminal function is crucial for chemosensory and somatosensory perception, environmental irritation detection, and triggering protective reflexes. Accurately assessing intranasal trigeminal function is thus essential. Since transient receptor potential (TRP) channels' activation mediates this function, their expression levels in the nasal mucosa may serve as potential indicators. The present study examined the relationship between intranasal trigeminal sensitivity, assessed via the lateralization task, and the messenger RNA (mRNA) expression levels of TRP channels using quantitative polymerase chain reaction (qPCR) in healthy individuals. The results indicated that individuals with lower lateralization scores exhibited significantly reduced TRPA1 mRNA expression levels, suggesting that TRPA1 density may influence behavioral responses to trigeminal stimulation. The findings provide promising evidence linking nasal TRPA1 expression to psychophysical measures, supporting the potential of nasal swabs as a simple, non‐invasive, biologically objective tool for assessing intranasal trigeminal function.