Phenotypical and molecular profiling of the extraneuronal cholinergic system of the skin

J Invest Dermatol. 2004 Nov;123(5):937-49. doi: 10.1111/j.0022-202X.2004.23425.x.


We present molecular and protein profiling of all acetylcholine receptors (ACh-R) in human scalp skin using PCR, in situ hybridization and double-labeling immunofluorescence. Within the epidermis, the nicotinic (n)ACh-R subunits, alpha3, alpha5, beta2, and beta4 were expressed in the basal cell layer (BCL) and in a single cell layer in the stratum granulosum; alpha9 was expressed in the basal and lower spinous layers. alpha7, alpha10, and beta1 were preferentially detected in the upper spinous and granular layers. Of the muscarinic (m)ACh-R, m1 and m4 were found in the suprabasal layers, whereas m2, m3, and m5 remained restricted to the lower layers. In the outer root sheath of the hair follicle, all ACh-R except alpha9, beta1, and m4 were found in the BCL whereas the alpha9, m4, and m5 ACh-R were restricted to the central cell layer. The alpha5, beta1, beta2, m1-m4 chains were strongly expressed in the inner root sheath. Undifferentiated sebocytes expressed the alpha3, alpha9, beta4, m3-m5 ACh-R whereas alpha7, beta2, beta4, m2, and m4 were found in mature sebocytes. In sweat glands, the alpha3*, alpha7, and m2-m5 ACh-R were most prominent in the myoepithelial cells whereas alpha9, beta2, m1, m3, and m4 ACh-R were present in the acinar cells. Taken together, our data result in a complete molecular map of the extraneuronal cholinergic system of the skin that may be translated into distinct functional reaction patterns.

MeSH terms

  • Animals
  • Antibodies
  • Cholinergic Fibers / physiology
  • Epidermis / innervation
  • Epidermis / physiology*
  • Gene Expression Profiling
  • Guinea Pigs
  • Hair Follicle / physiology
  • Humans
  • Immunohistochemistry
  • Phenotype
  • Polymerase Chain Reaction
  • RNA, Messenger / analysis
  • Receptors, Muscarinic / genetics*
  • Receptors, Muscarinic / metabolism
  • Receptors, Nicotinic / genetics*
  • Receptors, Nicotinic / metabolism
  • Scalp / innervation
  • Scalp / physiology
  • Sebaceous Glands / physiology
  • Sweat Glands / physiology


  • Antibodies
  • RNA, Messenger
  • Receptors, Muscarinic
  • Receptors, Nicotinic