Exposure to hypertonic conditions is known to produce pain and activate small-diameter sensory neurons. Recently, the vanilloid receptor variant and stretch-inactivated ion channel (SIC) was cloned and shown to mediate an inward current in response to cell shrinkage. Since other vanilloid receptors have been previously shown to mediate nociception, we investigated whether SIC is expressed in sensory neurons. Using reverse transcription-polymerase chain reaction and in situ hybridization techniques, we identified SIC in the neurons of dorsal root and trigeminal ganglia. Furthermore, SIC was found to be present almost exclusively in the small-diameter sensory neurons, which includes the nociceptive population. Since SIC is activated by cell shrinkage, it may participate in the mediation of pain produced by hypertonic stimuli.