Abstract
1. The changes in neuromuscular facilitation produced by varying extracellular calcium and magnesium concentrations have been studied at the frog neuromuscular junction using intracellular recording and automatic averaging of responses.2. When [Ca] was elevated three effects were observed: a large increase in transmitter release by the first impulse; a decrease in facilitation at short intervals between impulses; and a prolongation of the time course of the facilitated release. If the release by the first impulse is kept at constant level, by raising both [Ca] and [Mg], facilitation becomes greater at all impulse intervals.3. The results have been discussed in terms of the hypothesis that the action of calcium is responsible for neuromuscular facilitation.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
