title: First appearance of laminin in peripheral nerve, cerebral blood vessels and skeletal muscle of the rat embryo Immunofluorescence study with laminin and neurofilament antisera.
abstract: The formation of basal laminae in peripheral nerve was studied by immunofluorescence with laminin antisera in the rat embryo. Peripheral nerves were identified with neurofilament antisera in double labeled sections. In the adult rat perineurium and endoneurium were uniformly decorated by the antisera. Sensory neurons in posterior root ganglia were surrounded by a laminin positive basal lamina. Laminin immunoreactivity was first observed in posterior spinal roots on day 14. Anterior spinal roots and peripheral nerves remained laminin negative until day 17. The adult pattern (uniform decoration of endoneurium in large and small nerve trunks) was only observed on day 21. The formation of a basal lamina surrounding posterior root ganglion neurons was still not completed in 3-day-old rats. The only laminin positive structures in the brain and spinal cord were the external basal laminae and the blood vessels. The external basal lamina was present at all stages of development. In the spinal cord and brain stem vascular basal laminae were first identified with laminin antisera on day 14, in the diencephalon and telencephalon on day 15. Laminin immunoreactivity in the basal laminae surrounding myotubes was first observed on day 16.
authors.affiliation: Department of Neuropathology and Spinal Cord Injury Research Laboratory, Harvard Medical School and West Roxbury Veterans Administration Medical Center, Boston, MA 02132, U.S.A.
authors.forename: A
authors.initials: A
authors.lastname: Bignami
authors.forename: N H
authors.initials: NH
authors.lastname: Chi
authors.forename: D
authors.initials: D
authors.lastname: Dahl