Axon-Schwann cell interaction in degenerating and regenerating peripheral nerve

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5006412

Pellegrino, R G

Severance of a peripheral nerve stimulates a characteristic sequence of events in the distal stump, including the dissolution of axons and myelin and the proliferation of Schwann cells within their basal lamina. The first part of this thesis employs the cat tibial nerve to examine the relationship between the spatio-temporal pattern of Schwann cell mitosis, loss of the structural and functional properties of axolemma, synthesis of P/sub 0/, the major myelin glycoprotein, and the clearance of morphological myelin. Induction of S phase was measured by determining the uptake of /sup 3/H thymidine into trichloroacetic acid (TCA) precipitates following a 3 hour in vitro incubation in Krebs-Ringers buffer containing /sup 3/H thymidine. Nerve transection stimulated a monophasic increase in /sup 3/H thymidine uptake that peaked at 4 days post-transection throughout an 80 mm length of distal stump. Light microscope autoradiography revealed prominent incorporation into Schwann cells of myelinated fibers. Nerve transection also produced dramatic changes in the intrafascicular binding of /sup 3/H STX which binds to voltage-sensitive sodium channels STX binding fell precipitously to 20% of normal at 4 days post-transection, concurrent with the peak of /sup 3/H thymidine uptake. In conclusion, these studies suggest: (a) Schwann cells divide more or less contemporaneously throughout the distal stump; (b) changes in axons rather than myelin are likely to stimulate the Schwann cell to divide; (c) mitosis regulates other events during Wallerian degeneration, including myelin degeneration and the clearance of sodium channels from nodal axolemma.

• Research Organization: Yeshiva Univ., New York (USA)
• OSTI ID: 5006412
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
AUTORADIOGRAPHY
AZINES
BIOLOGICAL RECOVERY
BIOLOGICAL REGENERATION
CARBOHYDRATES
CATS
CELL CONSTITUENTS
CELL DIVISION
CELL MEMBRANES
GLUCOPROTEINS
HETEROCYCLIC COMPOUNDS
INJURIES
LABELLED COMPOUNDS
MAMMALS
MEMBRANES
MITOSIS
MYELIN
NERVE CELLS
NERVES
NERVOUS SYSTEM
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROTEINS
PYRIMIDINES
RECOVERY
RIBOSIDES
SACCHARIDES
SOMATIC CELLS
THYMIDINE
TRITIUM COMPOUNDS
VERTEBRATES