Neuromuscular Junction and Cholinergic Inhibitors Quiz

Nicotinic Receptor at the Neuromuscular Junction (NMJ)

• The nicotinic receptor at the NMJ is responsible for transmitting neuronal signals to skeletal muscles.

Receptors in Skeletal Muscles at the NMJ

• Skeletal muscles at the NMJ express nicotinic receptors, specifically the nicotinic acetylcholine receptor (nAChR).

Targets for Drugs at the NMJ

• Possible targets for drugs acting at the NMJ include nicotinic receptors, acetylcholine release, and cholinesterase.

Cholinergic Inhibitors at the Skeletal NMJ

• Cholinergic inhibitors primarily target the breakdown of acetylcholine at the skeletal NMJ.

Treatment of Myasthenia Gravis

• The main therapeutic strategy for the treatment of myasthenia gravis is to increase the amount of acetylcholine available at the NMJ.

Symptoms of Anticholinesterase Poisoning

• Symptoms of anticholinesterase poisoning include muscarinic symptoms (salivation, lacrimation, urination, defecation), nicotinic symptoms (muscle weakness, paralysis), and central nervous system symptoms (confusion, agitation).

Cholinesterase Inhibitors

• The primary function of cholinesterase inhibitors is to increase the amount of acetylcholine available at the NMJ by inhibiting its breakdown.

Botulinum Toxin

• The mechanism of action of Botulinum toxin is to cleave the SNARE protein, preventing the release of acetylcholine from the neuron.
• The main therapeutic use of Botulinum toxin is for the treatment of muscle spasms and dystonias.

Succinylcholine

• Succinylcholine is a depolarizing NM blocker.
• The primary metabolic pathway for succinylcholine is through pseudocholinesterase.

Reversal of Non-Depolarizing NM Blockers

• Sugammadex is a drug used for the reversal of non-depolarizing NM blockers like rocuronium.

Pralidoxime

• The main therapeutic use of pralidoxime is to treat anticholinesterase poisoning.

Immunosuppressive Treatment in Myasthenia Gravis

• The primary function of immunosuppressive treatment in myasthenia gravis is to reduce the production of autoantibodies against the nicotinic receptor.

Symptoms of Acute Intoxication with Cholinesterase Inhibitors

• The mnemonic 'DUMBBELL' represents the symptoms of acute intoxication with cholinesterase inhibitors: D - diarrhea, U - urination, M - miosis, B - bradycardia, B - bronchospasm, E - emesis, L - lacrimation, L - loss of strength.

Nervous System Response

• Parasympathetic activation is associated with the release of acetylcholine and stimulation of the muscarinic and nicotinic receptors.

Test your knowledge on neural signalling to skeletal muscle and drugs acting at the neuromuscular junction. Learn about the chain of events during nicotinic transmission, actions of cholinergic inhibitors, and their off-target effects.