Acetylcholine in Neuromuscular Junction


Acetylcholine is a molecule that the neuron releases over time into a space near the muscle. The acetylcholine released into that space is broken down by an enzyme.


When in the space, acetylcholine binds to the acetylcholine receptors on the muscle cell and allows sodium ions (Na+) to enter the muscle cell.

a) What determines the concentration of acetylcholine near the muscle cell at any given time?


b) In a disease called Myasthenia Gravis, a person has fewer acetylcholine receptors and weaker muscle contraction. One treatment for this disease is to administer a drug that blocks the activity of the enzyme that breaks down acetylcholine. Blocking the enzyme increases the concentration of acetylcholine near the muscle cell.  How does this treatment produce a stronger muscle contraction in a patient with Myasthenia Gravis?


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This material is based upon work supported by the National Science Foundation (DUE grants: 1438739, 1323162, 1347740, 0736952 and 1022653). Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the NSF.