Figure 3.

Illustration of a punch skin biopsy on eccrine sweat glands to quantify the cholinergic sudomotor nerve fibers. The specimen is fixed, sectioned, and stained with antibodies for PGP 9,5 (the pan axonal marker), tyrosine hydroxylase (a sweat gland neuroendocrine cell marker), and VIP (a marker for sympathetic nerve fibers) to highlight the sought-after tissue. Further various quantitation methods are applied to assess the sweat gland nerve fiber density. Based on this technique pilomotor and vasomotor autonomic nerve fibers can be quantified by using suitable staining methods. A comparison of the determined nerve fiber density to those of normative datasets gives information about the functionality and condition of the autonomic nervous system innervating skin organs.