Abstract
β,β′-Iminodipropionitrile (IDPN) produces neurofilamentous giant axonal swellings in proximal internodes of large myelinated axons. Secondary demyelinative changes result from the production of these axonal enlargments. Electrophysiological studies have demonstrated profound alterations in the electrical properties of motor neurons (MN) within the spinal cord. On the basis of intracellular recordings, it has been suggested that electrical contacts may exist between swollen axons and neighboring MN. In addition, the possibility remained that synaptic contacts develop on demyelinated axonal swellings. In the present study, we report the lack of either synapses on demyelinated axonal swellings or direct electrical contacts between neighboring MN. Axonal swellings are surrounded by attenuated processes of glial cells (probably fibrillary astrocytes), a finding discussed in terms of its possible role in the production of ephaptic transmission. There was considerable variation in the degree of axonal enlargements and in the extent of secondary (passive and active) demyelination. It is suggested that these morphological changes may represent structural correlates of some electrophysiological alterations observed in IDPN neuropathy.
Original language | English (US) |
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Pages (from-to) | 205-213 |
Number of pages | 9 |
Journal | Brain research |
Volume | 362 |
Issue number | 2 |
DOIs | |
State | Published - Jan 8 1986 |
Keywords
- axonal swelling
- ephaptic transmission
- glial cell
- motor neuron
- neurofilament
- paranodal demyelination
- synapse
- β,β′-iminodipropionitrile (IDPN)
ASJC Scopus subject areas
- General Neuroscience
- Molecular Biology
- Clinical Neurology
- Developmental Biology