The purpose of the present study was to determine gene expression pattern of chemosensitive receptor VR1 in the brain stem of the neonatal rat after low-level gaseous formaldehyde exposure. Male Sprague-Dawley newborn rats were exposed to clean air or 1.8mg/m3 formaldehyde for consecutive 72 h and the brain stems were dissected for RNA extraction. The mRNA levels of VR1 and cytokine NGF gene were determined with semiquantitative RT-PCR. We observed that the mRNA expression of VR1 and NGF was significantly increased in the brain of the tested neonatal rats. These findings suggest that successiv...