Myasthenia Gravis involves a shortage of receptors for which neurotransmitter?

Myasthenia Gravis involves a shortage of receptors for which neurotransmitter?

• A. Norepinephrine
• B. Dopamine
• C. GABA
• D. Acetylcholine

Answer: (D)

Communication at the neuromuscular junction hinges on acetylcholine binding to nicotinic receptors on the muscle membrane. In myasthenia gravis, antibodies target and reduce the number of these acetylcholine receptors, so fewer receptors are available to respond to ACh. This makes it harder for the signal to reach the threshold needed to trigger a muscle action potential, leading to muscle weakness that worsens with use. The other neurotransmitters listed are not the ones operating at the somatic neuromuscular junction, so they don’t explain this condition.

Communication at the neuromuscular junction hinges on acetylcholine binding to nicotinic receptors on the muscle membrane. In myasthenia gravis, antibodies target and reduce the number of these acetylcholine receptors, so fewer receptors are available to respond to ACh. This makes it harder for the signal to reach the threshold needed to trigger a muscle action potential, leading to muscle weakness that worsens with use. The other neurotransmitters listed are not the ones operating at the somatic neuromuscular junction, so they don’t explain this condition.