Sensory and autonomic innervation of non-hairy and hairy human skin

Summary Non-hairy and hairy human skin were investigated with the use of the indirect immunohistochemical technique employing antisera to different neuronal and non-neuronal structural proteins and neurotransmitter candidates. Fibers immunoreactive to antisera against neurofilaments, neuron-specific enolase, myelin basic protein, protein S-100, substance P, neurokinin A, neuropeptide Y, tyrosine hydroxylase and vasoactive intestinal polypeptide (VIP) were detected in the skin with specific distributional patterns. Neurofilament-, neuron-specific enolase-, myelin basic protein-, protein S-100-, substance P-, neurokinin A-and vasoactive intestinal polypeptide (VIP)-like immunoreactivities were found in or in association with sensory nerves; moreover, neuron-specific enolase-, myelin basic protein-, protein S-100, neuropeptide Y-, tyrosine hydroxylase- and vasoactive intestinal polypeptide (VIP)-like immunoreactivities occurred in or in association with autonomic nerves. It was concluded that antiserum against neurofilaments labels sensory nerve fibers exclusively, whereas neuron-specific enolase-, myelin basic protein- and protein S-100-like immunoreactivities are found in or in association with both sensory and autonomic nerves. Substance P- and neurokinin A-like immunoreactivities were observed only in sensory nerve fibers, and neuropeptide Y- and tyrosine hydroxylase-like immunoreactivities occurred only in autonomic nerve fibers, whereas vasoactive intestinal polypeptide (VIP)-like immunoreactivity was seen predominantly in autonomic nerves, but also in some sensory nerve fibers.     

Tyrosine hydroxylase- and neuropeptide Y-immunoreactive nerve fibers in the pineal complex of untreated rats and rats following removal of the superior cervical ganglia

Summary The distribution of tyrosine hydroxylase (TH)- and neuropeptide Y (NPY)-immunoreactive(IR) nerve fibers in the pineal complex was investigated in untreated rats and rats following bilateral removal of the superior cervical ganglia. In normal animals, a large number of TH- and NPY-IR nerve fibers were present in the pineal capsule, the perivascular spaces, and intraparenchymally between the pinealocytes throughout the superficial pineal and deep pineal gland. A small number of TH-IR and NPY-IR nerve fibers were found in the posterior and habenular commissures, a few fibers penetrating from the commissures into the deep pineal gland. To elucidate the origin of these fibers, the superior cervical ganglion was removed bilaterally in 10 animals, and the pineal complex was examined immunohistochemically. Two weeks after the ganglionectomy, the TH-IR and NPY-IR nerve fibers in the superficial pineal gland had almost completely disappeared. On the other hand, in the deep pineal and the pineal stalk, the TH-IR and NPY-IR fibers were still present after ganglionectomy. These data show that the deep pineal gland and the pineal stalk possess an extrasympathetic innervation by TH-IR and NPY-IR fibers. It is suggested that the extrasympathetic TH-IR and NPY-IR nerve fibers innervating the deep pineal and the pineal stalk originate from the brain.