Authors
  Navarro X.  Verdu E.  Wendelscafer-Crabb G.  Kennedy WR.
Title
  Innervation of cutaneous structures in the mouse hind paw: a confocal
  microscopy immunohistochemical study.
Source
  Journal of Neuroscience Research.  41(1):111-20, 1995 May 1.
Abstract
  The normal innervation of structures in mouse foot pads was investigated
  with immunohistochemistry and confocal microscopy. Nerves were visualized
  by incubating Zamboni fixed, thick, frozen sections with antibodies to
  protein gene product 9.5 (PGP 9.5), vasoactive intestinal peptide,
  substance P, calcitonin gene-related peptide, and protein zero. The
  antibodies were localized using cyanine 3.18 labeled anti-rabbit gamma
  globulin. PGP 9.5 immunolocalization showed dense nerve bundles at the
  base of the foot pad with branches to larger blood vessels, sweat glands
  and epidermis. Sweat gland tubules were surrounded by numerous sudomotor
  axons; single fibers accompanied the sweat duct toward the skin's surface.
  Nerve bundles containing myelinated and unmyelinated axons ran through and
  around the centrally located sweat gland cluster to end in free nerve
  endings and Meissner's-like corpuscles at the apex of the foot pad. Other
  bundles running parallel to the epidermis gave arcuate branches that
  supplied epidermis on the sides of the pads with a rich nerve network,
  principally with free nerve endings that often reached the most
  superficial cell layers of epidermis. Calcitonin gene-related
  peptide-immunoreactive (-ir) nerves were distributed to dermis and
  epidermis in lower density than PGP 9.5-ir fibers. Substance P-ir fibers
  were less numerous; most terminated as free endings in deeper layers of
  epidermis. Vasoactive intestinal peptide-ir nerves almost exclusively
  innervated sweat glands, ducts and blood vessels, but not epidermis. The
  mouse hind paw has potential to serve as a model system for investigations
  of functional and morphological changes that affect peripheral and
  autonomic nerves under diverse experimental conditions.