Conotoxin is a toxin that affects neurotransmitter receptors and ion channels, leading to diaphragm paralysis and respiratory arrest.

Conotoxin is a toxin that affects neurotransmitter receptors and ion channels, leading to diaphragm paralysis and respiratory arrest.

• A. Conotoxin
• B. Saxitoxin
• C. Tetrodotoxin
• D. Botulinum neurotoxin

Answer: (A)

Toxins that disrupt neuromuscular signaling by targeting receptors and ion channels can produce diaphragm weakness and respiratory arrest. Conotoxins, derived from cone snail venom, are a broad group of peptide toxins that act directly on neurotransmitter receptors and various ion channels at synapses. By modulating nicotinic acetylcholine receptors and/or blocking or altering voltage-gated ion channels (such as sodium or calcium channels), they prevent effective transmission at the neuromuscular junction, leading to diaphragm paralysis and dangerous respiratory failure. Saxitoxin and tetrodotoxin primarily block voltage-gated sodium channels, stopping action potentials and causing paralysis, but they don’t typically act on receptors in the same synaptic sense. Botulinum neurotoxin, on the other hand, inhibits acetylcholine release from presynaptic terminals rather than acting on receptors or ion channels. The description highlighting effects on receptors and ion channels fits conotoxin best.

Toxins that disrupt neuromuscular signaling by targeting receptors and ion channels can produce diaphragm weakness and respiratory arrest. Conotoxins, derived from cone snail venom, are a broad group of peptide toxins that act directly on neurotransmitter receptors and various ion channels at synapses. By modulating nicotinic acetylcholine receptors and/or blocking or altering voltage-gated ion channels (such as sodium or calcium channels), they prevent effective transmission at the neuromuscular junction, leading to diaphragm paralysis and dangerous respiratory failure.

Saxitoxin and tetrodotoxin primarily block voltage-gated sodium channels, stopping action potentials and causing paralysis, but they don’t typically act on receptors in the same synaptic sense. Botulinum neurotoxin, on the other hand, inhibits acetylcholine release from presynaptic terminals rather than acting on receptors or ion channels. The description highlighting effects on receptors and ion channels fits conotoxin best.