MCP 28: Synaptic Transmission Flashcards
neuromuscular junction (NMJ)
allows for nerve control of skeletal muscle, point of contact between nerve and muscle
end plate
AKA the neuromuscular junction
end plate potential (EPP)
not an action potential, depolarizes the cell so enough voltage gated Na+ channels open to produce an action potential in the muscle
excitatory postsynaptic potential (EPSP)
AKA end plate potential
excitation-secretion coupling
process by which depolarization increases free cytosolic calcium that in turn induces vesicle fusion and exocytosis of neurotransmitter from the presynaptic membrane
active zone
in the presynaptic membrane, NT-containing vesicles fused along in the inner leaflet of membrane in parallel rows
acetylcholine (ACh)
neurotransmitter, each vesicle contains 100mM of ACh
curare
competitive antagonist to ACh
alpha bugarotoxin
non-competitive antagonist to ACh
basal lamina
space between the pre and post-synaptic clefts
acetylcholinesterase (AChE)
cleaves ACh into choline and acetate; found int he basal lamina
myastemia gravis
autoimmune disease where antibodies block the AChR
junctional folds
located on post-synaptic membrane, 1.) membrane invaginations increase the surface area of the post synaptic membrane, therefore, more space for AChR receptors 2) also decrease distance between pre and post synaptic membrane, increase speed at which signal travels
development and innervation
with development, polyneural innervation ends; each muscle fiber is contacted by a single axon, but a single motor axon can innervate several muscle fibers
dystrophin
links muscle membrane to actin cytskeleton, giving structure to the NMJ; gene defects can result in muscular dystrophy
