Wagner - Synaptic transmission I Flashcards
What is synaptic transmission?
Process of neuronal communication with other neurons and effector systems within region known as the synapse
List the 3 pre-synaptic anatomical features
- Terminal/bouton at distal end of axon
- Numerous mitochondria and synaptic vesicles w/in boutons
- Synaptic cleft
Axon terminals align with post-synaptic density that are loaded with what (3)?
- neurotransmitter receptors
- intracellular scaffolding proteins
- Enzymes
What three things can a terminal contact and what are the types named?
- Dendrites = axodendritic
- Cell body (soma) = axosomatic
- Other axons = axo-axonal
What are synaptic vesicles derived from and what do they express?
derived from endosomes and express neurotransmitter transporters
What do the transporters enable the synaptic vesicles to do?
enable them to be filled with neurotransmitter
What triggers the fusion of the synaptic vesicle with the terminal membrane allowing it to release neurotransmitter via EXOCYTOSIS?
The Ca2+ influx (created by action potential inducing depolarization that activated the voltage-gated Ca2+ channels)
What two proteins assist synaptic vesicle in docking on the terminal membrane in order to fuse?
membrane- associated proteins SYNAPTOBREVIN and SYNTAXIN by formation of a SNARE complex
Where does vigorous exocytosis occur?
at the active zone
What 3 things are contained in high density in the active zone?
- voltage-gated Ca2+ channels
- fusion/scaffolding proteins
- docking proteins
What are spent vesicles coated with and what happens to them?
coated with clathrin and undergo endocytosis to be recycled back into endosome
What elicits a post-synaptic response?
sufficient neurotransmitter release (stimulated by Ca2+)
What are the differences between Type I and Type II synapses?
Type I: excitatory/asymmetric, wide cleft and active zone, and well developed post-synaptic density
Type II: inhibitory/symmetric, narrow cleft and active zone, and less prominent post-synaptic density
