Pharmacology and Pathologies of NMJ

curare

competitive antagonist blocks Ach receptor on motor end plate, prevents EPP generation and leads to paralysis; lethal injection

eserine

Ach esterase inhibitor; blocks degradation of Ach and boosts transmission; reverse effects of sedatives

succinylcholine

Ach receptor antagonist; binds and depolarizes motor end plate and not depolarized by Ach esterase fast enough so no repolarization, desensitization paralysis

botox

cleaves snare proteins that dock Ach for exocytosis; prevents Ach release and causes flaccid paralysis

myasthenia gravis

body produces antibodies that lead to destruction of Ach receptor, EPP fails to reach threshold for AP, droopy eyelids

LEMS

mutation in calcium channel, decreases amount of Ach that gets released; not enough stimulation causes muscle weakness

guillan barre syndrome

demyelinating disease where system attacks glial cells; slows conduction velocity, being locked inside body

dystonia

involuntary sustained muscle contractions, repetitive movements; blepharospasm and parkinsons disease

blepharospasm

spasm of muscle surrounding tear duct even at rest