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. Author manuscript; available in PMC: 2020 Aug 1.
Published in final edited form as: Neuromuscul Disord. 2019 Jul 5;29(8):614–617. doi: 10.1016/j.nmd.2019.07.001

Table 1.

Summary of in vitro electrophysiology, acetylcholine receptor (AChR) count and ultrastructure of endplate regions (EP-R) findings [5].

Findings
In vitro microelectrode recordings

  • Miniature endplate potential: amplitude ↓ (59% of nl)

                   decay time mildly ↑ (146% of nl)

  • Quantal content of endplate potential: ↓ (42% of nl)

  • Number of releasable quanta: ↓ (50% of nl)

  • Probability of quantal release: nl
Endplate AChR count

  • Mildly ↓ (77% of nl)
Endplate ultrastructure

  • Simplified or absent junctional folds (40% EP-R)

  • Partial occupancy of postsynaptic region by nerve terminal (18% EP-R)

  • Dilated vesicles in junctional sarcoplasm (47% EP-R)

  • Schwann cell encasement of nerve terminals (5.5% EP-R)

  • Degenerating junctional folds (3.6% EP-R)

  • Reduced postsynaptic area of folds and clefts (44% of nl)

  • Reduced postsynaptic membrane density (64% of nl)

  • Structurally normal presynaptic nerve terminals

The EP-R was defined as the nerve terminal and associated postsynaptic region; one endplate may have more than one region [5]. ↑, increased; ↓, reduced; nl= normal.