Double-label immunohistochemistry of whole-mount, adult rat dura mater with anti-glial cell line-derived neurotrophic factor family receptor α3 (GFRα3) and (A) anti-tyrosine hydroxylase (TH) or (B, C) anti-calcitonin gene-related peptide (CGRP), showed GFRα3-like immunoreactivity (-LI) in sympathetic efferents and peptidergic sensory afferents, respectively. (C) Enlarged portion of boxed area in B showing GFRα3-LI fibers that do not show CGRP-LI. (D) Controls in which the primary antibody was omitted show lack of reactivity. Scale bars, 100 μm.