Fig. 7

Percentage of C-fibers activated by pruritogens, the number of activation periods and cumulative latency increase. A Percentage of C-fibers activated by β-alanine, BAM 8-22 or cowhage extract, showing the percentage of activated (blue), non-activated (gray) and activated with a “slow bursting pattern” (red) mechanosensitive (CM), very high threshold (VHT) and mechano-insensitive (CMi) fibers. The number of fibers is shown within the columns. B In a subgroup of the fibers shown in A, β-alanine and BAM 8-22 were tested sequentially, and histamine was applied to CMi-fibers. The size of the circle indicates the number of fibers activated by β-alanine (blue), BAM 8-22 (green) or histamine (red) and the numbers are given in the same color. The number of fibers co-activated by β-alanine and BAM 8-22 is shown in bold black. C–F Number of activation periods (y-axis) and cumulative latency increase (x-axis) during activation after treatment with either C β-alanine or D BAM 8-22. E Cumulative latency increases during activation caused by BAM 8-22 and cumulative latency increase during activation by β-alanine only in those fibers in which activation by both substances could be quantified. F Activation periods triggered by BAM 8-22 and β-alanine in those fibers in which activation by both substances could be quantified. In C and D, more fibers are depicted than in E and F because the responses could not be reliably quantified or both injections performed in all fibers