- 1.
Long-term facilitation (LTF) and short-term facilitation (STF) at excitatory neuromuscular junctions were studied under conditions of varying [K+]0 and with the addition of strophanthidin.
- 2.
The magnitude of LTF varied inversely with [K+]0, while STF was unaffected.
- 3.
Strophanthidin concentrations greater than 10−5 M greatly increased LTF, but not STF.
- 4.
Both LTF and STF were unaffected by large decreases in excitatory junctional potential amplitude produced by the addition of GABA or Mn+2.
- 5.
The results support the hypothesis that LTF is a consequence of Na+ accumulation in presynaptic terminals and behaves independently of STF.
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© 1980 by Company of Biologists
1980