|
|
||||||||
1. A sublethal quantity of black widow spider venom was injected into the calf muscles of mice. After 30 min to 6 weeks soleus muscles were examined by light and electron microscopy and by electrophysiological techniques. 2. Within 30 min motor nerve terminals were swollen and depleted for synaptic vesicles and by 6 h were disrupted and engulfed by Schwann cells. By 24 h every end-plate examined was denervated. Some preterminal myelinated axons also showed degenerative changes. 3. Re-innervation was first seen at 2 days. By 3 days axon terminals were present at most end-plates and by 8 days their morphology was nearly normal. The normal pattern of innervation of the muscle was re-established in that axons re-innervated their original end-plates and very few ultraterminal axonal sprouts were found. 4. Physiological study showed complete failure of transmission and absence of miniature end-plate potentials (m.e.p.p.s) and end-plate potentials (e.p.p.s) until day 3, when muscles responded weakly to indirect stimulation and m.e.p.p.s were recorded at 30% and e.p.p.s at 40% of fibres. The mean quantal content of e.p.p.s was low and there was rapid fatigue on repetitive stimulation. Extrajunctional sensitivity to acetylcholine developed within 1 day, was maximal at 3 days and declined to normal at 12-14 days. 5. The proportion of fibres at which m.e.p.p.s and e.p.p.s were recorded returned to normal by day 6 and mean quantal content was normal by day 9. 6. These findings show that the re-innervation of original end-plates is of importance in facilitating the rapid return of transmission to normal levels and limiting the extent of axonal growth.
This article has been cited by other articles:
![]() |
G. M. O'Hanlon, P. D. Humphreys, R. S. Goldman, S. K. Halstead, R. W. M. Bullens, J. J. Plomp, Y. Ushkaryov, and H. J. Willison Calpain inhibitors protect against axonal degeneration in a model of anti-ganglioside antibody-mediated motor nerve terminal injury Brain, November 1, 2003; 126(11): 2497 - 2509. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. J. Willison and N. Yuki Peripheral neuropathies and anti-glycolipid antibodies Brain, December 1, 2002; 125(12): 2591 - 2625. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. M. O'Hanlon, J. J. Plomp, M. Chakrabarti, I. Morrison, E. R. Wagner, C. S. Goodyear, X. Yin, B. D. T. Trapp, J. Conner, P. C. Molenaar, et al. Anti-GQ1b ganglioside antibodies mediate complement-dependent destruction of the motor nerve terminal Brain, May 1, 2001; 124(5): 893 - 906. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |