Synaptic NT release, Signaling, and Removal

What does the ability to release NT after TTX exposure if the there is a big enough change in deltaV of the presynaptic membrane?

It means that NaV channels are not required for the release of NT

What does the ability to release NT after TEA exposure blocking Kv channels tell you about the requirement for NT release?

Kv channels are not required for NT release

What does a change in postsynaptic membrane potential correlate with?

Ca2+ entry

What do synapsins do?

They anchor vesicles

What does CAM kinase do?

It phosphorylates synapsins causing the release of vesicles

What happens to calcium when it enters a presynaptic cell?

It interacts with calmodulin to phosphorylate synapsins and release vesicles

What does Rab3 do?

With the addition of GTP it moves vesicles to the membrane

What are the 2 Ca2+ dependent effects in the presynaptic cell?

1. Initiate exocytosis

2. Replenish reusable pool

What is the difference between v-SNARE and t-SNARE?

V are in the vesicle

T are in the membrane

What do SNAREs do?

They prepare vesicles for release

What is Ca2+ relationship with SNARE?

When calcium enters the cell it interacts with SNAREs, this is the critical step in exocytosis

What effect does tetanus poisoning have on muscles?

It inhibits glycine release making it impossible for muscles to relax

What do BoTox toxins inhibit the release of?

Ach

What does MUNC do?

It is a calcium dependent method for moving vesicles to the docking region

What are the 3 steps for Ca2+ dependent docking?

1. Priming

   1. Interact with each other

2. Superpriming

   1. Complexin interacts with snares to bring vesicles closer to the membrane

3. Fusion-pore opening

   1. 5 Ca bind to different proteins and open the vesicle (noncooperative)

What does Gabapentin do?

It prevents Ca2+ from entering the cell, preventing vesicle RELEASE

What is the NT fate of biogenic amines (serotonin, dopamine, etc)

SERTs

What breaks down serotonin?

Monoamine oxidase

What is the uptake mechanism for Glycine, GABA, GLutamate?

AA, EAAT, SNAT

GABA + osmolyte transporters

What do all the NT uptake mechanisms rely on?

NaV channels

Where is there cholinergic excess?

1. Autonomic ganglion

2. Parasympathetic postganglionic

3. Neuromuscular junction

What can you use to block cholinergic excess in parasympathetic postganglionic areas?

Atropine