Conditioning nerve crush accelerates cytoskeletal protein transport in sprouts that form after a subsequent crush

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Journal of Comparative Neurology; (USA)

DOI:https://doi.org/10.1002/cne.903050113· OSTI ID:5545722

McQuarrie, I G; Jacob, J M ^[1]

---

1. Case Western Reserve Univ., Cleveland, OH (USA)

To examine the relationship between axonal outgrowth and the delivery of cytoskeletal proteins to the growing axon tip, outgrowth was accelerated by using a conditioning nerve crush. Because slow component b (SCb) of axonal transport is the most rapid vehicle for carrying cytoskeletal proteins to the axon tip, the rate of SCb was measured in conditioned vs. sham-conditioned sprouts. In young Sprague-Dawley rats, the conditioning crush was made to sciatic nerve branches at the knee; 14 days later, the test crush was made where the L4 and L5 spinal nerves join to form the sciatic nerve in the flank. Newly synthesized proteins were labeled in motor neurons by injecting {sup 35}S-methionine into the lumbar spinal cord 7 days before the test crush. The wave of pulse-labeled SCb proteins reached the crush by the time it was made and subsequently entered sprouts. The nerve was removed and sectioned for SDS-PAGE and fluorography 4-12 days after the crush. Tubulins, neurofilament proteins, and representative 'cytomatrix' proteins (actin, calmodulin, and putative microtubule-associated proteins) were removed from gels for liquid scintillation counting. Labeled SCb proteins entered sprouts without first accumulating in parent axon stumps, presumably because sprouts begin to grow within hours after axotomy. The peak of SCb moved 11% faster in conditioned than in sham-conditioned sprouts: 3.0 vs. 2.7 mm/d (p less than 0.05). To confirm that sprouts elongate more rapidly when a test crush is preceded by a conditioning crush, outgrowth distances were measured in a separate group of rats by labeling fast axonal transport with {sup 3}H-proline 24 hours before nerve retrieval.

• OSTI ID: 5545722
• Journal Information: Journal of Comparative Neurology; (USA), Journal Name: Journal of Comparative Neurology; (USA) Vol. 305:1; ISSN 0021-9967; ISSN JCNEA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
AMINO ACIDS
ANIMALS
AZOLES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTROPHORESIS
EVEN-ODD NUCLEI
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
INJURIES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAMMALS
MEMBRANE TRANSPORT
METHIONINE
NERVES
NERVOUS SYSTEM
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PROLINE
PROTEINS
PYRROLES
PYRROLIDINES
RADIOISOTOPES
RATS
RODENTS
SCIATIC NERVE
SCINTILLATION COUNTING
SULFUR 35
SULFUR ISOTOPES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES