Mary, a 45-year-old lady from Bangalore suffers from botulism poisoning. This toxin blocks the release of acetylcholine and has the effect of:: (A) Inhibiting adrenergic synapse transmission, (B) Facilitating adrenergic synapse transmission, (C) Inhibiting cholinergic synapse transmission, (D) No effect on synaptic transmission
Answer is C. The botulinum toxin blocks the release of acetylcholine and has the effect of inhibiting cholinergic synapse transmission. Because there is an insufficient quantity of acetylcholine to open channels that allow for the influx of sodium ions into the muscle fiber, the end-plate potential is inadequate to cause an action potential. The neurotransmitters located at adrenergic synapses include epinephrine and norepinephrine but not acetylcholine.