What question did this study set out to answer?

To determine the relationship between external calcium concentration and excitatory neuromuscular transmission in crayfish muscle fibers.

January 1, 1970The Journal of PhysiologyOpen Access

Effect of calcium on excitatory neuromuscular transmission in the crayfish

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Authors

HBHumberto BrachoBenemérita Universidad Autónoma de Puebla RORichard K. OrkandUniversidad Nacional de Educación a Distancia

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Implication

In vitro study shows that extracellular calcium increases quantal transmitter release at crayfish neuromuscular junctions, demonstrating presynaptic control of synaptic strength.

Key Points

To determine the relationship between external calcium concentration and excitatory neuromuscular transmission in crayfish muscle fibers.
Examined in vitro crayfish neuromuscular preparations across external calcium concentrations ranging from 1.8 to 30 mM/l (1/8 to 2 times normal).
Recorded transmembrane junctional potentials from muscle fibers and extracellular junctional currents near nerve terminals using electrophysiological techniques.
Excitatory junctional potential amplitude was proportional to external calcium raised to the power n, with n ranging from 0.68 to 0.94 (mean 0.82) between 1.8 and 15 mM/l.
Elevated external calcium amplified junctional potentials primarily by increasing the average number of transmitter quanta released per presynaptic impulse, while quantum size, synaptic delay, presynaptic potentials, and muscle membrane properties remained largely unaffected.

Cite This Study

Bracho et al. (1970) studied this question.

synapsesocial.com/papers/6a93ffdd0ab6c6af028c0b8b https://doi.org/10.1113/jphysiol.1970.sp008997

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Implication

In vitro study shows that extracellular calcium increases quantal transmitter release at crayfish neuromuscular junctions, demonstrating presynaptic control of synaptic strength.

Effect of calcium on excitatory neuromuscular transmission in the crayfish

Discussion

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Implication

Key Points

Cite This Study

Effect of calcium on excitatory neuromuscular transmission in the crayfish

Discussion

Member takes

Implication

Key Points

Cite This Study

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