Biomaterial Database

Facilitation and delayed release at single frog neuromuscular junctions. 1986

I S Cohen, and W Van der Kloot

Facilitation and delayed spontaneous release were recorded from neuromuscular junctions at 2 temperatures. In some experiments, Sr2+ substituted for Ca2+. We measured the ratio of delayed release to resting spontaneous release (D), and the ratio of the second end-plate potential amplitude to the first (F). An extension of the model of Barton et al. (1983) relating Ca2+ to evoked and spontaneous release is presented. If residual Ca2+ accounts for facilitation and delayed release, then D must be greater than F. In all of our experiments, D was greater than F. We conclude that residual Ca2+ is sufficient to account for facilitation and delayed release at the frog neuromuscular junction. However, D falls abruptly at a time when F is almost unaltered, which raises serious difficulties in accepting the residual calcium hypothesis.

UI	MeSH Term	Description	Entries
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D008959	Models, Neurological	Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.	Neurologic Models,Model, Neurological,Neurologic Model,Neurological Model,Neurological Models,Model, Neurologic,Models, Neurologic
D009469	Neuromuscular Junction	The synapse between a neuron and a muscle.	Myoneural Junction,Nerve-Muscle Preparation,Junction, Myoneural,Junction, Neuromuscular,Junctions, Myoneural,Junctions, Neuromuscular,Myoneural Junctions,Nerve Muscle Preparation,Nerve-Muscle Preparations,Neuromuscular Junctions,Preparation, Nerve-Muscle,Preparations, Nerve-Muscle
D011894	Rana pipiens	A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.	Frog, Leopard,Leopard Frog,Lithobates pipiens,Frogs, Leopard,Leopard Frogs
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013324	Strontium	An element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures