Synaptic transmission! Flashcards
What forms Gap Junctions?
Are gap junctions specific??
Connexins! They form the channel
Gap junctions are very non specific
They are important in the heart!
V-SNAREs are located where and used for what?
Location = the vesicle
They are used during DOCKING which is when the vesicle is held near the membrane
What are the two subunits that makeup V-SNARES?
Which one binds Ca++?
- Synaptobrevin
- Synaptotagmin
Synaptotagmin binds Calcium!
Brevin and Tagmin!
Where are t-SNAREs and what are they used for?
Location: In the presynaptic membrane!!
They are used for docking and eventually priming!
What triggers priming?
Binds to?
What does this cause?
Ca++ influx where Ca++ binds to synaptotagmin?
Causes hemifusion!!
What is the exception to an IPSP?
Normally an IPSP is a type of hyperpolarization!
Exception is when Cl- channels are opened! This causes a depolarization, BUT it goes to a resting potential that is still below the threshold and resists movement towards the threshold.
Therefore, it is still an IPSP!
Temporal summation vs Spatial summation
Temporal = impulses over time! – when they are close enough they can summate
Spatial == 2 synapses near each other can summate if sent at the same time!
Synaptic plasticity?
What is this important for?
Increase in strength and size of dendritic spines!
This is important for learning and memory.
Via reorganization of actin filaments!
3 types of axonal transport!
Anterograde
- FAST
- SLOW
Retrograde
Speeds for fast/slow anterograde and retrograde axonal transport?
Fast anterograde = 400mm/day
Slow anterograde = 1-2 mm/day
Retrograde = 200mm/day
What is the rate limiting process for neuronal regeneration/repair?
Slow anterograde axonal transport!!! 1-2mm/day
