Figure 2From: No relevant modulation of TRPV1-mediated trigeminal pain by intranasal carbon dioxide in healthy humans Nociceptive properties of nasally insufflated CO 2 . Pain ratings on a numerical rating scale from 0 to 10 during nasal insufflation of CO2 with a flow of 1 l/min for 20 min. Error bars are given as standard error of the mean.Back to article page