Figure 4.

C-tactile (CT) afferent response to histamine. A: response to slow brushing (1 cm/s) in CT unit before iontophoresis. B: single-unit example of response to the same stimulus after histamine iontophoresis. C: wheal and flare to confirm reaction. D: mean and standard error (SE) of firing rate for individual units before (pre) and after (post) iontophoresis (mean of both units pre = 28 Hz, SE = ±3.8 Hz and post = 23 Hz, SE = ±3.3 Hz). Histamine was applied in n = 5 units. Brushing pre- and post histamine was recorded for n = 2 units.