Figure 2.

In vivo acetylcholine release from human skin assayed by dermal microdialysis in the presence and absence of neostigmine. Dermal microdialysis from 34 volunteers in the presence of 1 μM neostigmine (top row) and four volunteers in the absence of neostimgine (bottom row). Given are the means±s.e.m. In the presence of neostigmine, much more acetylcholine could be found in the samples.